Displaying items by tag: Gemmology

An Exclusive Interview with Gem Cutter John Dyer

Belinda Morris talks to renowned and much-admired lapidary John Dyer, one of the speakers at the 2016 Gem-A Conference, about the science and art of gem cutting. 

Did you train as a gemmologist or gem cutter?

I loved gems and business from an early age. I was also home-schooled and one of my parents’ strategies for teaching me was to purchase books on subjects I was interested in, so they bought books on gems and gemmology for me (Gem Identification Made Easy by Antoinette Matlins and Antonio C. Bonanno was one of the first) and that stoked my interest.

At 16 I wanted to start in the gem business and my dad said he would help me out. One thing led to another and we ended up going to Zambia to buy gemstones. We bought rough gems instead of cut ones to get a better deal and when we brought them back we took them to a cutter to have them cut. He did a really bad job on them and charged us a lot of money for it. 

This resulted in us getting mad and buying a faceting machine because, as my father said: “We can do that well, or better, ourselves, and cheaper too!” This all turned out to be a blessing in disguise because it helped us to discover that I love to cut gems. So although the gems we bought on that trip were not super profitable in the end, it started us in the direction of what has now become the focus of our business - high quality and creative gem-cutting. 

I never had any formal training. There were no lapidaries interested in teaching near me that I knew of, and as far as gemmology goes I mainly learned from books and practical experience. I would consider myself a far better cutter than gemmologist, but I do have certain practical, applicable gemmological techniques which help me when purchasing rough. Rough is almost easier to ID than cut gems, because you often still have the crystal habit, visible cleavage planes and more inclusions and other factors to help identify a gem and potential treatments it may have undergone. 

A 28.03 ct Citrine DreamscapeTM. Photo by John Dyer.
A 28.03 ct Citrine DreamscapeTM. Photo by John Dyer

Does the stone influence your design or do you choose the stone based on a particular cutting style that you want to see? 

The shape, colour and clarity of the rough are the main considerations in choosing the cut I am going to do. Usually I buy the best rough I can find and then cut to what I feel is best suited to it. There are times when I don’t buy a piece because I feel the shape and size it could cut would not have good marketable appeal, but other than that I pretty much let the rough dictate to me what it wants to be (that’s within certain limitations of marketability and visual appeal, of course). 

That challenge that each gem represents - trying to bring out its maximum potential - is one of the things I most enjoy about cutting. There are so many considerations that go into it and for the most part all those decisions are made on the fly as I saw and preform (pre-shape) the gem for dopping and faceting or carving. 

What is your favourite stone to work with and do you have a preferred design for it? 

My favourite gem to work with is aquamarine since it comes in reasonably large and clean gems, is easy to polish and has great transparency so it is well suited to a wide variety of different cutting styles. Also, since it isn’t dark, it shows the cut well instead of hiding it like some extra dark gems do. 

A 13.07 ct Aquamarine StarBrite TM. Photo by Lydia Dyer.
A 13.07 ct Aquamarine StarBriteTM. Photo by Lydia Dyer

There are sometimes cutting styles I prefer for specific gems; those with high dispersion (e.g. zircon) do better with flat faceted cuts than with concave facets or carving, since those tend to reduce the dispersion. Other gems with low dispersion I love to cut with concave facets or carving styles since they can increase the brilliance. It’s all part of the decision making process when deciding what to cut a specific piece or rough into. 

A 46.81 ct Aquamarine Super Trillion TM. Photo by John Dyer.
A 46.81 ct Aquamarine Super TrillionTM. Photo by John Dyer

You use many less well-known gemstones, do you find that this increases the public’s awareness of these stones, highlighting how beautiful they can be?

As far as using ‘less well-known’ gems go I find that the market is much more accepting of a wide range of gems than in the past. TV shopping has introduced many strange gem types to a large public audience and a certain percentage of that public has gone on to learn a lot about gems and become educated and sophisticated buyers. This, coupled with how expensive the ‘traditional’ gems have become, has really opened a wide door to the lesser known gems. 

That being said though, most of the gems I cut are still within the parameters of what is familiar to most jewellers - aquamarine, beryl, morganite, citrine, amethyst, ametrine, garnet of all kinds, sapphires, emerald, ruby, peridot, tourmaline (all colours), spinel and zircon make up most of my inventory.

Morganite StarBriteTM 50.92 ct cut by John Dyer & Co. Photo by Lydia Dyer.
Morganite StarBriteTM 50.92 ct cut by John Dyer & Co. Photo by Lydia Dyer

Sometimes I will do a very rare gem, such as bicolour spessartite, phenakite, oligoclase or similar, but they are the exception rather than the rule.

What do you endeavour to reveal in stones? 

Essentially what I am looking to reveal is the full potential for beauty that is in each piece of rough. So much labour goes into the searching for and mining of gem rough that I feel it should be cut in a manner that respects its true rarity and uniqueness. But at the same time some sacrifices of size and weight will need to be made for the gem to achieve its maximum beauty. That is the goal that I aim for. 

What do you look for when selecting a piece of rough? 

When selecting rough I look at the size, shape and clarity of each piece. I also take into account the value of the finished piece because there is a lot of labour involved in our cutting and if the finished value of the gem is too low we will not recoup our labour costs. For that reason there are some pieces of rough that are cool and pretty but I just can’t buy them because they won’t generate a profit. 

Do you travel to mines around the world to procure your own rough or do you often buy at shows? 

I have travelled to various countries in search of gems. My most valuable gem (my wife) is Brazilian from the state of Paraíba so the search has paid off! However, gems are often found in very small quantities and a trip direct to the mines can be a fruitless affair since there might not be any production for months at a time. This often results in my needing to buy from middlemen of some kind. Over the years we have formed relationships with a number of rough suppliers who bring us a variety of rough, that it would have been very hard to have access to on our own. After all, cutting is a time consuming business and if I spent all my time running about after rough I wouldn’t get much cutting done. 

Have you had any major cutting catastrophes? 

Major cutting catastrophes are something you like to put out of your mind, but there have been a number of them over the years. There was the kilo of pink tourmaline rough we heated without grinding clean first and broke almost all of it. There was a bixbite (red beryl) from Utah that cost us thousands of that we hoped to get over a carat’s worth of finished cut stone out of it, but it shattered due to internal stress and we ended up with three very small gems from it. There was the imperial topaz that I was carving and got too hot and broke it in half… and many other gems that have broken during carving, or been chipped or something similar. Over 20 plus years of cutting there are a lot of things like that which happen.

Talk us through the process of one of your famous cuts such as the Super Trillion™. What’s the process of cutting a gem in this way? How long does it take to cut some of your most famous designs?? 

The Super Trillion™ is all flat faceted and is an adaptation of a cut that was explained to me by Chris Remen (now deceased) which over time I tweaked to make a number of improvements to. The result is a semi-traditional looking trillion which I feel is super. Since it has so many facets it is very time-consuming to cut. How long it takes depends completely on the type of material and the size of the gem but it usually takes a day or longer to complete. 


A 26.11 ct Citrine Super TrillionTM. Photo by John Dyer.A 26.11 ct Citrine Super TrillionTM. Photo by John Dyer

Do you have any advice for people who want to take up lapidary? 

To take up lapidary as a hobby, the best thing to do is search for a local lapidary club. Often there will be retired members who will teach cutting for a very reasonable price and this often allows you to avoid the initial relatively high cost of the machinery and supplies. For those who want to make this a profession, I would recommend studying the market to be sure that it is really what they want to do… because it is not the easiest thing to make money at. 

You need to be a skilled cutter (something that often takes five years or more to accomplish) and make large investments in raw materials if you are going to sell your own gems. If you don’t sell your own gems, you are going to need to find a niche market for your cutting services and be very fast if you expect to make money because much of the gem trade is used to Asian pricing on gem cutting and that is hard to compete against until you educate your clientele about the difference in look and quality. That means a lot of outreach and marketing is involved. 

Rare red beryl (bixbite), cut by John Dyer & Co. Photo by Lydia Dyer.
Rare red beryl (bixbite), cut by John Dyer & Co. Photo by Lydia Dyer

You’ve won many awards for your work; which means the most to you? 

The award that means the most to me is the first place I took recently at the German Award for Jewellery and Precious Stones Idar-Oberstein 2015. This is one of my favourite competitions, but the fact that you have to adhere to a theme makes it more complicated. You might have a perfectly beautiful idea for a gemstone cut, but it must go with the theme to win. The theme in 2015 was ‘Light My Fire’, so I thought that an orange gem would fit well with the idea of fire. With this in mind, I searched through my stock of rough and selected a deep orange citrine, which, once ground clean, was a flame shape. Despite this it was still a challenge to decide what to do with the underside of the gem to make it look like fire. However, an idea came to me to execute a pattern that I had never done or seen before and which required an adaptation of my existing machinery and techniques - the result is a gem with a flame shape, but which also has little flame-shaped internal facets on the back which reflect light individually with varying intensities so that they look like flames shooting upwards as the gem is moved. 

John Dyer's flame-cut citrine, first place winner in the 2015 German Award for Jewellery and Precious Stones in Idar-Oberstein. Photo by Lichtblick Foto-Design, Hiltrud & Jurgen Cullmann of Schwollen, Germany.
John Dyer's flame-cut citrine, first place winner in the 2015 German Award for Jewellery and Precious
Stones in Idar-Oberstein. Photo by Lichtblick Foto-Design, Hiltrud & Jurgen Cullmann of Schwollen, Germany

Where do you see yourself going with your talent? What’s next for you in the lapidary world? 

It might not be super romantic, but I guess what I see is gradually improving what I already do and adding new styles and techniques to that. As a result of this I feel that each year our gems are better cut, more beautiful and more saleable. ■   

To view John Dyer's work click here

This article originally appeared in Gems&Jewellery Sept/Oct 2016 / Volume 25 / No. 5 pp. 28-32

Interested in finding out more about gemmology? Sign-up to one of Gem-A's courses or workshops.

If you would like to subscribe to Gems&Jewellery and The Journal of Gemmology please visit Membership.


Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Gem-A tutor Barbara Kolator B.Sc. M.Sc. FGA DGA EG shares some highlights from her recent trip to the Institut de Gemmologie de Madagascar in Antananarivo, which is a proud Gem-A Accredited Teaching Centre (ATC). 

Read more


Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Famous for her ostentatious sense of style, 18th century French Queen Marie Antoinette was back as the centre of attention at Sotheby's in November thanks to the record-breaking sale of her natural pearl and diamond pendant. Here, Beth West FGA DGA EG considers the history behind this fascinating piece. 

Read more


Birthstone Guide: Tanzanite for Those Born in December

Birthstone Guide: Tanzanite for Those Born in December

Looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers the December birthstone tanzanite and how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Journal Digest: Bumble Bee Stone from Indonesia

Journal Digest: Bumble Bee Stone from Indonesia

Guy Lalous ACAM EG delves into an article on Indonesian Bumble Bee Stone (BBS) from The Journal of Gemmology Volume 36, No.3, and presents his edited take on the most essential information, findings and lessons to be learnt. Continue reading here...

Read more


Retail Focus: Beyond the Green

Retail Focus: Beyond the Green

From the Summer 2018 issue of Gems&Jewellery, Gem-A Gemmology Tutor Beth West FGA DGA EG explores Colombian emeralds. 

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Additional Info

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Getting to Grips with GemTOF Technology

This article by Guy Lalous ACAM EG digests a technical article from The Journal of Gemmology and discusses the capabilities of Laser Ablation Inductively Coupled Plasma Time-of-Flight Mass Spectrometry (LA-ICP-TOF-MS) compared to conventional Inductively Coupled Plasma Quadrupole Mass Spectrometry (ICP-Q-MS). Potential applications of this new analytical technique are also described.  

Gem testing has evolved into an advanced materials science using sophisticated instrumental technologies for detailed chemical and structural analyses. The chemical analysis of gem materials allows identification of synthetics and treatments. Trace-element analysis is useful to identify the geographical origin of high-end stones. When the origin of a stone has a significant impact on it’s value, the cost associated with this technique may be  justified.

Six Blue Sapphires Medium Sized Image
Six blue sapphires (various client stones weighing approximately 2–36 ct) are shown on an historical map of the famous gem locality of Mogok, Myanmar. Quantitative chemical data can be helpful for determining the geographic origin of sapphires. Map from Gordon (1888); photo by L. E. Cartier and Julien Xaysongkham, SSEF.

How does LA-ICP-MS work?

 The LA-ICP-MS analysis process can be thought of in two main parts: material sampling i.e. Laser Ablation (LA) and chemical analysis i.e. Inductively Coupled Plasma Mass Spectrometry (ICP-MS). A tiny, nearly invisible ablation pit is caused by the laser, into the girdle of the gemstone. There will be minimal damage as the laser vaporises only a microscopic amount of the sample for analysis. It nebulizes the material and the aerosol produced is transferred in a gas stream to an ICP-MS for elemental and/or isotopic analysis. An ICP-MS combines a high-temperature Inductively Coupled Plasma (ICP) with a Mass Spectrometer (MS).   The ICP is an ionisation source where the energy is supplied by electric currents, which ionises the atoms. These ions are then separated based on their mass-to-charge ratio (m/Q) and detected by the MS.  

What is LA-ICP-MS used for?

LA-ICP-MS is recognised as one of the most important spectrometric techniques and has been used in gemmology for quantitative chemical analysis. It provides data that can be used to create chemical fingerprint diagrams for geographical origin determination.

What is ICP-Q-MS?

There are multiple varieties of ICP-MS instruments, which use different mass-separation schemes in analysis. Of these the ICP-Q-MS, which uses a quadrupole is the most popular. The quadrupole is a mass filter. The quadrupole consists of four cylindrical rods arranged so that the ionised sample travels down the centre. Depending on the electro-magnetic field of the rods, the trajectory of the ionised particles is affected, with selected ionic weights based on the m/Q being filtered out and the ions of interest reaching the MS detector. The ability to filter ions on their m/Q allows ICP-MS to supply isotopic information. Different isotopes of the same element have different masses.

What are the limitations of ICP-Q-MS?

The user of this technique has to define a preselected list of isotopes. Isotopes are sequentially measured one at a time, the ‘limited’ sample volume is divided (segmented) between all measured isotopes, thereby drastically reducing the effective sensitivity if many isotopes are monitored.

What are the capabilities of ICP-TOF-MS?

ICP-TOF-MS is one of the latest and most advanced technologies in the ICP-MS family. Time-Of-Flight (TOF) uses the principle that the ‘flight’ duration for one ion passing through a fixed flight tube is related to its m/Q.  Lighter ions take less time to travel the same distance compared to their heavier counterparts with the same charge, provided they have identical kinetic energy, therefore achieving mass separation. ICP-TOF-MS acquires spectra from the lightest to the heaviest isotopes at a higher speed as well as achieving a better resolving power than conventional Q-MS. It ‘snaps pictures’ of the full and continuous mass spectrum without the need to assign isotopes of interest. Such a spectrum reveals almost the full elemental composition, reaping the benefits of the robust plasma source and there is no need to re-ablate the stone due to an incomplete or ‘badly’ chosen predefined list of isotopes.

What practicalities are there to consider with ICP-TOF-MS?

Due to technical limitations the ICP-TOF-MS model described in this article cannot measure light isotopes while maintaining a high sensitivity for heavy isotopes. It takes two measurements to complete the full elemental analysis from Lithium to Uranium. Limit of detection (LOD) values range from single-digit parts per billion (ppb) for heavy elements to low parts per million (ppm) for light elements. TOF-MS provides better LOD than Q-MS. TOF-MS collects all information in the full mass spectrum with no information loss.

Figure 2 Journal Digest LA-ICP-TOF-MS
(a) An averaged full elemental mass spectrum is shown from a LA-ICP-TOF-MS measurement of NIST610, a silicate standard reference material. Mass-to-charge ratios through the entire elemental range were acquired simultaneously. (b) Details of the orange region in (a) illustrate the mass resolving power of of TOF-MS (m/Δm ≈ 3,000), which is better than quadrupole MS (normally m/Δm≈ 300) in resolving some interferences.

What are the potential applications?

The possibilities of the technique will enhance applications such as trace-element characterisation of gemstones and pearls for origin determination and treatment detection, and will open new research opportunities for age dating, inclusion studies and high-spatial-resolution chemical mapping of gems.

The new instrument is called GemTOF and was installed at SSEF in July 2016. ■  

To find out more information about this exciting technique visit GemTOF

This is a summary of an article that originally appeared in The Journal of Gemmology entitled ‘Simultaneous High Sensitivity Trace-Element and Isotopic Analysis of Gemstones Using Laser Ablation Inductively Coupled Plasma Time-of-Flight Mass Spectrometry’ by Hao A.O. Wang, Michael S. Krzemnicki, Jean-Pierre Chalain, Pierre Lefèvre, Wei Zhou and Laurent E. Cartier 2016 / Volume 35 / No. 3 pp. 212-222

Interested in finding out more about gemmology? Sign-up to one of Gem-A's courses or workshops.

If you would like to subscribe to Gems&Jewellery and The Journal of Gemmology please visit Membership.


Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Gem-A tutor Barbara Kolator B.Sc. M.Sc. FGA DGA EG shares some highlights from her recent trip to the Institut de Gemmologie de Madagascar in Antananarivo, which is a proud Gem-A Accredited Teaching Centre (ATC). 

Read more


Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Famous for her ostentatious sense of style, 18th century French Queen Marie Antoinette was back as the centre of attention at Sotheby's in November thanks to the record-breaking sale of her natural pearl and diamond pendant. Here, Beth West FGA DGA EG considers the history behind this fascinating piece. 

Read more


Birthstone Guide: Tanzanite for Those Born in December

Birthstone Guide: Tanzanite for Those Born in December

Looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers the December birthstone tanzanite and how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Journal Digest: Bumble Bee Stone from Indonesia

Journal Digest: Bumble Bee Stone from Indonesia

Guy Lalous ACAM EG delves into an article on Indonesian Bumble Bee Stone (BBS) from The Journal of Gemmology Volume 36, No.3, and presents his edited take on the most essential information, findings and lessons to be learnt. Continue reading here...

Read more


Retail Focus: Beyond the Green

Retail Focus: Beyond the Green

From the Summer 2018 issue of Gems&Jewellery, Gem-A Gemmology Tutor Beth West FGA DGA EG explores Colombian emeralds. 

Read more


Additional Info

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Harrods Unearths 228.31 ct Diamond from its Vaults for Private Sale

London department store Harrods has delved into its vault to unveil a 228.31 ct diamond for the first time.

Nicknamed ‘The Harrods Diamond’ by its anonymous owner, the stone has been released from the retailer’s safety deposit vault and is now available to view by appointment only.

The pear-shaped, G-colour, VS1-clarity polished diamond can be counted among the world’s rarest, largely due to its incredible size but also its exceptional cut and symmetry.

While the majority of large diamonds are sold at auction, Harrods is offering interested parties the chance to buy this diamond privately on a first come, first serve basis.

Read more: The History of Diamonds in Engagement Rings

Chief merchant at Harrods, Helen David, comments: “We are thrilled to unveil one of the world’s rarest diamonds, the so-called Harrods Diamond, named after the iconic Knightsbridge store.  It is rare that stones of this weight, cut, polish and symmetry are sold outside auction, so this is an exceptional opportunity for Harrods’ customers and a very exciting moment in Harrods’ history.”

228.31 ct Harrods' Diamond
The 228.31 ct Harrods Diamond. Image courtesy of Harrods

Harrods has long offered its most affluent customers access to its Victorian-era safe deposit facilities, comprising small boxes all the way up to whole strong rooms. All are available for fixed annual rates and are accessible via a single key, which remains in the customer’s possession at all times.

Although the price of the Harrods Diamond is only available upon application, predictions have been made as to the final figure.

In 2013, Christie’s auctioned one of the world’s most exceptional pear-shaped diamonds – an internally flawless, 101.73 ct, D-colour gem with perfect symmetry. It was eventually purchased for $26,746,541 (£21.5m).

Although the Harrods Diamond differs in colour, its larger size and luxurious association is likely to see its price soar to more than £20 million. ■  

Interested in finding out more about diamonds? Sign-up to one of Gem-A's diamond courses or workshops.

If you would like to subscribe to Gems&Jewellery and The Journal of Gemmology please visit Membership.

Cover image courtesy of Harrods.


Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Gem-A tutor Barbara Kolator B.Sc. M.Sc. FGA DGA EG shares some highlights from her recent trip to the Institut de Gemmologie de Madagascar in Antananarivo, which is a proud Gem-A Accredited Teaching Centre (ATC). 

Read more


Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Famous for her ostentatious sense of style, 18th century French Queen Marie Antoinette was back as the centre of attention at Sotheby's in November thanks to the record-breaking sale of her natural pearl and diamond pendant. Here, Beth West FGA DGA EG considers the history behind this fascinating piece. 

Read more


Birthstone Guide: Tanzanite for Those Born in December

Birthstone Guide: Tanzanite for Those Born in December

Looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers the December birthstone tanzanite and how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Journal Digest: Bumble Bee Stone from Indonesia

Journal Digest: Bumble Bee Stone from Indonesia

Guy Lalous ACAM EG delves into an article on Indonesian Bumble Bee Stone (BBS) from The Journal of Gemmology Volume 36, No.3, and presents his edited take on the most essential information, findings and lessons to be learnt. Continue reading here...

Read more


Retail Focus: Beyond the Green

Retail Focus: Beyond the Green

From the Summer 2018 issue of Gems&Jewellery, Gem-A Gemmology Tutor Beth West FGA DGA EG explores Colombian emeralds. 

Read more


Additional Info

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The French Gem Connection

Gem-A Accredited Teaching Centre (ATC) the Laboratoire de Gemmologie de Marseille (LGM) recently held its 5th Annual Gemmologist Conference. Katherine Palthey FGA, one of the speakers at the event summarises the day. 

On Sunday 11 December LGM held their Conference at the Mercure Hotel in Marseille France. The Director Agata Cristol FGA DGA organised a successful Conference with guests such as Thierry Pradat FGA of Gems-Plus and guest speakers Alexandre Eichler FGA, Katherine Palthey FGA, Laurent Seneca FGA and Bruno Cupillard FGA.

The topics discussed during the Conference were centered on gem treatments and their impact on retail prices. Alexandre Eichler FGA, Director of Gems River, specialises in sapphires and has spent months in numerous sapphire mines this year confronted with both ‘old burn’ (traditional heating) and ‘new burn’ (heating with diffusion) treatments. He pointed out in detail the differences between the methods and the impact they have on today’s market prices. 

Natural unheated sapphires, LGM blogpost
A rare pair of 6.01 ct natural unheated sapphires from Bo Phloi. Photo credit Alexandre Eichler, Gems River

Katherine Palthey FGA, Gem Expert Consulting, presented Burmese lavender jadeite and the origins of its colour, which is manganese. Burmese lavender jadeite shows an absorption band at 437 nm and a large absorption near 580 nm for manganese. Colour treated jade and imitations have a different spectrum, demonstrating they are not Burmese lavender jadeite. After an intricate explanation on differentiating natural jade from treated jade (shown in the figure below) she announced her research results on over 50 jadeite pieces and shared her inside secrets on how to identify high quality jadeite.

Burmese lavender jadeite options A,B, and C in LGM blogpost
L-R: Burmese natural lavender jade, colour treated jade and an impressive imitation made of Calcite. Photo credit Katherine Palthey FGA, Gem Expert Consulting

Laurent Seneca FGA lives between Colombia and Monaco and dedicates his time to fine quality Colombian emeralds. Laurent explains how the past 20 years have seen an enormous increase in the use of synthetic epoxy resins to enhance emerald’s clarity. He has seen an alarming rise in polymer resins such as Gematrat and Permasafe, being used on Colombian emeralds and he explained the long term implications of these treatments. In the Bogota market alone, he estimates up to 95% of the emeralds today are being treated with hardened epoxy resins.

Colombian emerald, LGM blogpost
1.4 ct natural emerald from Muzo, Colombia. Photo credit Laurent Seneca FGA

Demonstration stations with microscopes between lectures were busy as guests rushed to see the latest in sapphire, jadeite and emerald treatments being introduced to the market this year. There was so much interest, Agata extended the day by an extra hour for our guests.

Guest of Honor, Bruno Cupillard FGA from Aventures Cristallines rounded up the day’s talks. Bruno is a successful mineral and gemstone photographer known for his unique and emotionally triggering views inside gemstones. The audience was taken behind his camera to see his secret photographic techniques, and he generously shared his tips on diffused lighting, background settings and more. He shared a breathtaking video on his photos of scenes and nature’s beauty presented in inclusions such as Paesine – a limestone that has split and shifted to create a scenic landscape…we were all mesmerized. 

Hotel Mercure served us their lovely French cuisine and after digesting our expressos, we jumped in to the Annual Gemmology Tournament. Organised by Thierry Pradat FGA of Gems-Plus, we were each passed 40 different gemstones and with one minute and just the loupe, we had to identify with precision all the material. The ambiance was relaxed and laughter bounced off the walls, although all eyes were on their loupes. Thierry Pradat FGA is one of France’s largest gemstone dealers and his business Gem-Plus is a true reference point for professional jewellers, designers and avid collectors. Thierry generously offered an amazing rhodolite garnet for the winner who was none other than our guest speaker Bruno Cupillard.

Thierry Pradat LGM blogpost
Thierry Pradat introducing the Annual Gemmology Tournament

Agata Cristol FGA DGA, took another minute at the close of the Conference, while waving the Gem Guide, to remind all of us to be cautious when classifying treatments on certificates and disclosing them to customers. The overall aim of the discussion was seeking international agreements on classifying treatments within these materials and to improve our commitment to ethical mining issues such as dynamiting the beautiful mountains in Colombia. A wonderful experience and I look forward to Conferences such as these in the future. ■  

Interested in finding out more about diamonds? Sign-up to one of Gem-A's courses or workshops.

If you would like to subscribe to Gems&Jewellery and The Journal of Gemmology please visit Membership.

Cover image 2016 Conference Speakers and Cecile Agu FGA. L-R: Alexandre Eichler FGA, Cecile Agu FGA, Katherine Palthey FGA, Bruno Cupillard FGA, Thierry Pradat FGA and Agata Cristol FGA DGA.


Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Gem-A tutor Barbara Kolator B.Sc. M.Sc. FGA DGA EG shares some highlights from her recent trip to the Institut de Gemmologie de Madagascar in Antananarivo, which is a proud Gem-A Accredited Teaching Centre (ATC). 

Read more


Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Famous for her ostentatious sense of style, 18th century French Queen Marie Antoinette was back as the centre of attention at Sotheby's in November thanks to the record-breaking sale of her natural pearl and diamond pendant. Here, Beth West FGA DGA EG considers the history behind this fascinating piece. 

Read more


Birthstone Guide: Tanzanite for Those Born in December

Birthstone Guide: Tanzanite for Those Born in December

Looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers the December birthstone tanzanite and how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Journal Digest: Bumble Bee Stone from Indonesia

Journal Digest: Bumble Bee Stone from Indonesia

Guy Lalous ACAM EG delves into an article on Indonesian Bumble Bee Stone (BBS) from The Journal of Gemmology Volume 36, No.3, and presents his edited take on the most essential information, findings and lessons to be learnt. Continue reading here...

Read more


Retail Focus: Beyond the Green

Retail Focus: Beyond the Green

From the Summer 2018 issue of Gems&Jewellery, Gem-A Gemmology Tutor Beth West FGA DGA EG explores Colombian emeralds. 

Read more


Additional Info

Read more...

Gem Central with Marcus McCallum FGA

Local gem-dealer Marcus McCallum FGA hosted this December’s Gem Central. Specialising in unusual and high quality stones, Marcus has spent forty years in the trade. Angharad Kolator Baldwin reports on the evening…

Marcus is based in Hatton Garden and has seen many changes in the trade in the last few decades. Attendees heard his take on trends in the industry, his personal views on gem testing and the challenges faced by gem dealers. Participants were lucky enough to look at stones from Marcus’ personal collection and view the fossils that kick-started his own love of mineralogy when he was just six years old.

Fossil Sea Urchin, from Marcus McCallum's personal collection, Gem Central Blogpost
Fossil Sea Urchin, from the personal collection of Marcus McCallum FGA

The Bruton room at Gem-A headquarters was packed with people who came to find out more from long standing member and supporter Marcus McCallum FGA. This Gem Central was the last Gem-A event of 2016 and it provided an excellent opportunity for gemmology enthusiasts to gather together, covet beautiful gemstones and enjoy a drink and a mince pie.

Marcus McCallum showing his personal collection at Gem Central
Marcus McCallum FGA and Gem Central attendees

So what has changed in the gem industry over the past 40 years? Marcus described how there used to be more small business in the trade, looking for unusual stones. He talked about the branding on stones and the concept of ‘best’ that is now so heavily sought after. This does not sit well with Marcus who believes it is the beauty of the gem that should be emphasised, whether it is pigeon blood in colour or not, beauty is the most important. 

Rutilated quartz; Marcus McCallum's personal collection, gem central blogpost
Rutile and haematite in quartz, from the personal collection of Marcus McCallum FGA

Historically buyers were not as interested in the origin of stones and the premiums seen today for Burmese rubies and Kashmir sapphires simply did not exist. He also remarked that dealers did not previously distinguish between heat treated and non-heat treated stones, in fact sapphires were routinely treated. The current trend in paying a higher price for non-heat treated stones is a good move in Marcus’ opinion. He does believe that you should pay a premium for untreated stones, but raised the question, does the origin truly matter?

Pinpointing the origin of a stone is a great challenge for gemstone dealers. Laboratory testing costs a great deal of money and this is not always paid off by the result. Marcus gave examples where multiple labs do not always return the same result for the same stone. He described how incredibly difficult it is to definitively locate the origin of a stone, partly due to the fact that the same mine can support very different mineralogical characteristics. 

Marcus called himself a romantic, preferring artisanal mining, where the revenue generated through the mine can trickle back down to the local community. He has travelled widely visiting different mines and finding some remarkable stones. He also believes it is down to the trade to look at how stones are marketed, how different localities are perceived by the commercial market and consumer, and to encourage the beauty of a stone to shine brighter than its locality. Gemmologists shouldn’t be afraid to rely on their own knowledge he said and challenge a gemstone certificate if necessary. 

Barbara Kolator looking through a loop at Gem Central with Marcus McCallum
Barbara Kolator FGA DGA looking through her loupe

Consumers are moving away from diamond engagement rings and Marcus said that colour is coming back. This is the opportunity for jewellers to educate consumers and weave a story around coloured stones. 

Gem Central, which is held once a month at Gem-A headquarters is a fantastic time for gemmology students and gem enthusiasts to have more practical opportunities and socialise with other individuals with the same interests. The events are hosted by a variety of speakers and no two evenings are ever the same. ■

Interested in attending a Gem Central event? For more information about our upcoming Gem Central events visit the Gem Central page or email events@gem-a.com.

Interested in finding out more about gemmology? Sign-up to one of Gem-A's courses or workshops.

Cover image goethite in ametrine, from the personal collection of Marcus McCallum FGA.


Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Gem-A tutor Barbara Kolator B.Sc. M.Sc. FGA DGA EG shares some highlights from her recent trip to the Institut de Gemmologie de Madagascar in Antananarivo, which is a proud Gem-A Accredited Teaching Centre (ATC). 

Read more


Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Famous for her ostentatious sense of style, 18th century French Queen Marie Antoinette was back as the centre of attention at Sotheby's in November thanks to the record-breaking sale of her natural pearl and diamond pendant. Here, Beth West FGA DGA EG considers the history behind this fascinating piece. 

Read more


Birthstone Guide: Tanzanite for Those Born in December

Birthstone Guide: Tanzanite for Those Born in December

Looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers the December birthstone tanzanite and how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Journal Digest: Bumble Bee Stone from Indonesia

Journal Digest: Bumble Bee Stone from Indonesia

Guy Lalous ACAM EG delves into an article on Indonesian Bumble Bee Stone (BBS) from The Journal of Gemmology Volume 36, No.3, and presents his edited take on the most essential information, findings and lessons to be learnt. Continue reading here...

Read more


Retail Focus: Beyond the Green

Retail Focus: Beyond the Green

From the Summer 2018 issue of Gems&Jewellery, Gem-A Gemmology Tutor Beth West FGA DGA EG explores Colombian emeralds. 

Read more


Additional Info

Read more...

Inside the World of Photomicrographer Danny Sanchez

Award-winning photographer Danny Sanchez GG, a speaker at the 2016 Gem-A Conference, reveals the secrets of photomicrography, the equipment he swears by and his favourite gemstones to photograph.

Q. What drew you towards photomicrography?

I was a working musician in Los Angeles and wanted a change of pace. I’d always loved gems and minerals and when I discovered that you could study them, their origins and applications, at the Gemological Institute of America, I couldn’t enrol quickly enough. The day I opened the course material and saw an inclusion photomicrograph, I was hooked.  

Q. What special equipment do you use?

I might be a little biased so I feel like a lot of my equipment is special. I think my most unusual piece of equipment is a vertical stepping rig that moves the microscope mere microns at a time.  

The home 'laboratory'
Danny Sanchez' home 'laboratory'

Q. Can you explain stacking for those that don’t know?

Microscopy deals in very narrow focal planes. A single photo has very little that is actually ‘in focus’. Focus stacking is a technique that allows one to merge multiple photos, each with different focal planes, into a single photo with greater depth of field. This is stacking. Using this technique, one is able to ‘manufacture’ depth. There is definitely a way to overuse stacking. Besides the visual residue that can be found in some photo ‘stacks’ (a group of photos merged into one), if a photo is rendered with too much depth, the viewer can lose perspective. Simply put, but somewhat counterintuitively, a photo with too much depth can look flat. 

A single photomicrograph play of colour in opal from Jalisco, Mexico. Field of view 3.05 mmThe complete stack of 81 photos. Field of view 3.05 mm

Left: A single photomicrograph play of colour in opal from Jalisco, Mexico. Field of view 3.05 mm. Right: The complete stack of 81 photos. Field of view 3.05 mm

Q. Do you look at images from earlier and wish you could retake some of the spectacular ones to add the ‘dimension’ it offers?

I definitely understand the impulse to go back and re-do a shot, but it’s not a strong one for me. I’m always trying to look forward, and to reproduce or re-tool an image I’ve already made seems like a step backward — particularly in light of how many dynamic subjects this industry offers. (For more information on stacking see Prince, N., ‘Use of Stacking Software for Expanding Depth-of-Field in Inclusion Photomicrography’, The Journal of Gemmology, 2014, 34(3), 188–89).  

Q. Do you have any advice for gemmologists wishing to try photomicrography at home?  

There are an overwhelming number of details to consider when trying to take a successful photograph through the microscope, and it’s hard to see the forest for the trees. The simplest recommendation I can make is: buy more light than is necessary. Gemmologists are used to using a specific type and amount of light during observation and imagine that will be sufficient when they sit down to take a photograph. It never is. Light is everything in photography; it’s even more important in photomicrography.  

Q. Do you have any particular favourite inclusions or gemstones to photograph?  

This past year I’ve immersed myself in opal with matrix. I have yet to find a mineral more dynamic that so readily yields actual landscapes. Part of what I look for in my own work is the feeling of being transported somewhere ‘other’. I enjoy the challenge of finding that in quartz or corundum, but when I work with opal in matrix, it’s almost like the photo takes itself.   

Opal from Magdalena. Jalisco, Mexico. Field of view 3.05 mm.
Opal from Magdalena. Jalisco, Mexico. Field of view 3.05 mm

Q. How do the public react to your photos? 

Most (non-gemmological) people don’t know what they’re looking at when standing in front of my photos. Once I tell them that it’s a photo of the inside of a gemstone, more often than not, they don’t believe me. Finally, when they do, they have a million questions. It’s really great to see people so invigorated about gems and minerals. I’m sure they’re much more interested when they leave than before they arrived. 

Ilmenite and hematite in orthoclase feldspar from Harts Range, Australia. Field of view 3.05 mm.
Ilmenite and hematite in orthoclase feldspar from Harts Range, Australia. Field of view 3.05 mm

Q. How do you source the stones that you work with? 

Mostly, I’ll buy at trade shows, looking through dealers’ back stock inventory — stones that, for one reason or another, have been passed over. Part of the joy of my process is these little discoveries and bringing something out of them that no one could have imagined. There’s something about owning the stones I work with (and hopefully producing an image from them) that makes the final product that much more satisfying. I’m not sure I can satisfactorily articulate why. Maybe, like every other gemmologist, I just like to hoard stones. 

Q. Do you see your photos as an educational tool or as an art form? 

Art is an inherently selfish act and mine is certainly no exception. All I ever wanted was to capture in my images a sense of mystery and wonder. It is purely self-serving and in this regard, it’s very ‘artsy’. But when people look at my images and discover that they are photos of actual minerals inside other minerals, there is an immediate spark of curiosity. The moment that happens, my photos become educational. 

Q. How long does it take you to capture the ‘magic’ shot? 

I’ll sit down with a parcel of stones and spend hours turning them over in my hands, changing the lighting environment, trying my best to disappear into the process. Once I’ve decided on which stone I’ll pursue, it could take another hour or so to test shoot dozens of lighting environments. The shooting and processing of a stack of 100 or more photos takes another 30 to 40 minutes. The real work happens over the following several days while I digitally develop the photo, just as I would if I were working in a traditional darkroom. 

Metal sulphide in fluorite, from Elmwood, Tennessee. Field of view 1.8 mm.
Metal sulphide in fluorite, from Elmwood, Tennessee. Field of view 1.8 mm

Q. What’s the most frustrating thing about photomicrography? 

The most frustrating thing is that I can’t do it for a living. My photos don’t have to be perfect, but they have to be representative of the view through my oculars, at the same time capturing the feeling of the moment of discovery. If I don’t feel I’ve done that after I’ve gone through the process of taking the shot(s) and developing the stack, it can be very frustrating. 

Q. What are your future plans for your work? 

Most of my work for the past few years has focused on atmosphere, the space within the stone and not any particular inclusion or the capturing of inclusions. That’s what interests me the most and that’s what I see myself pursuing; capturing and creating the space within gems. 

Q. If fleeing a burning building, what equipment do you grab?

Luckily for me, I’m not a photographer in the traditional sense of the word. I didn’t grow up aspiring to take photos nor did my penchant for gadgetry lean in that direction. My entry into the world of ‘prosumer’ cameras and lenses began with photomicrography. Because of this, I don’t have a collection of lenses or cameras that would make it hard to choose if fleeing a burning building. My most crucial pieces of equipment fit into one small hard case. I’m definitely fortunate in that regard. 

Q. Your studio improvisations suggest you have a good eye for engineering solutions to suit your needs…

Everything I have done, I’ve done on the shoulders of others. Of course, I’d like to think of myself as a tinkerer and problem solver but most of my equipment has existed in some form, on someone else’s desk, in someone else’s setup. It wasn’t easy piecing it all together but with help from a very small handful of people from around the globe, I’ve put together something that I’m really proud of. 

Q. Another big part of the job these days is software; how do you select the software you use? 

I’ve mentioned the stacking software and while that’s a tricky nuanced piece of software, it performs one function and is therefore finite in its ability to affect a photograph. Beyond that there is developing software such as Lightroom and Photoshop. Together, they can be used to alter an image in infinite ways. While they are indispensable tools, I try to remain as faithful to the view through my oculars as possible. 

Q. What are the ‘frontiers’ to be explored in photomicrography? 

I think the frontiers of photomicrography lay in the direction of software. We’re so lucky to be living in a time of amazing advances, in what computers can do to aid in our perception of the world around us. One day I hope to be able to pop on a pair of VR glasses and take a flight through a Kashmir sapphire or Mexican opal. 

Q. Do you have any gemmological heroes? 

Of course, Eduard Gübelin and John Koivula. Without their work, who knows where I’d be. 

Q. Who first encouraged you to be a photographer? 

In 2007, a year or so after I bought my first microscope, I was working at a trade show and was introduced to Edward Boehm. I already knew who he was, both in the trade and his family’s importance in gemmology. I shook his hand and told him, with no small amount of youthful hubris, that I was going to be a photomicrographer. He flashed me that great smile and told me to go for it. Every subsequent time I ran into him, he would always ask how it was going and if I’d made any progress with my photos. I was the smallest blip in his periphery but for the next five years he never forgot to ask about my photos. During that time I struggled with the pursuit itself and a lot of self-doubt. It wasn’t until 2013 that I was proud enough of my work to share it with the general public. His polite consideration was such a small gesture but it made me think: if this great gemmologist, grandson of the man who helped pioneer this field, hasn’t forgotten about me and my pursuit, I can’t forget either. ■   

To view more of Danny Sanchez's work click here or visit his Instagram @mineralien

This article originally appeared in Gems&Jewellery May/June 2016 / Volume 25 / No. 3 pp. 10-12

Interested in finding out more about gemmology? Sign-up to one of Gem-A's courses or workshops.

If you would like to subscribe to Gems&Jewellery and The Journal of Gemmology please visit Membership.

Cover image Opal, from Jalisco, Mexico. Field of view 3.05 mm. All images courtesy of Danny Sanchez. 


Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Gem-A tutor Barbara Kolator B.Sc. M.Sc. FGA DGA EG shares some highlights from her recent trip to the Institut de Gemmologie de Madagascar in Antananarivo, which is a proud Gem-A Accredited Teaching Centre (ATC). 

Read more


Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Famous for her ostentatious sense of style, 18th century French Queen Marie Antoinette was back as the centre of attention at Sotheby's in November thanks to the record-breaking sale of her natural pearl and diamond pendant. Here, Beth West FGA DGA EG considers the history behind this fascinating piece. 

Read more


Birthstone Guide: Tanzanite for Those Born in December

Birthstone Guide: Tanzanite for Those Born in December

Looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers the December birthstone tanzanite and how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Journal Digest: Bumble Bee Stone from Indonesia

Journal Digest: Bumble Bee Stone from Indonesia

Guy Lalous ACAM EG delves into an article on Indonesian Bumble Bee Stone (BBS) from The Journal of Gemmology Volume 36, No.3, and presents his edited take on the most essential information, findings and lessons to be learnt. Continue reading here...

Read more


Retail Focus: Beyond the Green

Retail Focus: Beyond the Green

From the Summer 2018 issue of Gems&Jewellery, Gem-A Gemmology Tutor Beth West FGA DGA EG explores Colombian emeralds. 

Read more


Additional Info

Read more...

Last Chance to See the Record-Breaking Foxfire Diamond at the Smithsonian

The largest known uncut, gem-quality diamond mined in North America is available to view at the Smithsonian’s National Museum of Natural History until February 2017.

The Foxfire Diamond, which weighs more than 187 carats, was unearthed in August 2015 at the Diavik Diamond Mind in the Barren Lands of Canada’s Northwest Territories. The site is just 130 miles from the Arctic Circle, leading those who discovered the gem to name it ‘Foxfire’ – inspired by an aboriginal description of the Northern Lights as similar to the swish of fox tails.

The discovery of the Foxfire caused something of a stir among miners in the region, who believed such large, gem-quality diamonds were unlikely to exist in the area. In fact, diamonds found over the previous decade generally peaked at six carats. Because of this, the mine’s equipment was configured to sift out stones smaller than six carats, while pulverising larger ones.

Read more: Harrods Unearths 228.31 ct Diamond from its Vaults for Private Sale

The 187.63 ct Foxfire should have been crushed, but its uncommonly flattened shape enabled it to safely pass through the filters.

Diamond enthusiasts in North America, or indeed those travelling to Washington D.C., are encouraged to see the Foxfire before it is removed from public view on February 16 2017. It will also be displayed alongside the infamous Hope Diamond in the Harry Winston Gallery of the museum.

Read more: An Exclusive Interview with Gem Cutter John Dyer

In June 2016, the Foxfire Diamond was acquired in an international auction by Deepak Sheth of Amadena Investments LLC/Excellent Facets Inc. Sheth elected to preserve the diamond intact, maintaining both its unique characteristics and interesting origin story.

He says: "Having North America’s largest known uncut, gem-quality diamond on display at the Smithsonian is a testament to the rarity of the Foxfire diamond. It also represents another significant chapter in the diamond’s remarkable story." ■  

Interested in finding out more about diamonds? Sign-up to one of Gem-A's diamond courses or workshops.

If you would like to subscribe to Gems&Jewellery and The Journal of Gemmology please visit Membership.

Cover image courtesy of Amadena Investments LLC.


Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Gem-A tutor Barbara Kolator B.Sc. M.Sc. FGA DGA EG shares some highlights from her recent trip to the Institut de Gemmologie de Madagascar in Antananarivo, which is a proud Gem-A Accredited Teaching Centre (ATC). 

Read more


Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Famous for her ostentatious sense of style, 18th century French Queen Marie Antoinette was back as the centre of attention at Sotheby's in November thanks to the record-breaking sale of her natural pearl and diamond pendant. Here, Beth West FGA DGA EG considers the history behind this fascinating piece. 

Read more


Birthstone Guide: Tanzanite for Those Born in December

Birthstone Guide: Tanzanite for Those Born in December

Looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers the December birthstone tanzanite and how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Journal Digest: Bumble Bee Stone from Indonesia

Journal Digest: Bumble Bee Stone from Indonesia

Guy Lalous ACAM EG delves into an article on Indonesian Bumble Bee Stone (BBS) from The Journal of Gemmology Volume 36, No.3, and presents his edited take on the most essential information, findings and lessons to be learnt. Continue reading here...

Read more


Retail Focus: Beyond the Green

Retail Focus: Beyond the Green

From the Summer 2018 issue of Gems&Jewellery, Gem-A Gemmology Tutor Beth West FGA DGA EG explores Colombian emeralds. 

Read more


Additional Info

Read more...

Gem-A Student Celebrates Southend Success at Houses of Parliament

Second generation family business C J Vinten, was recently invited to exhibit its wares at the Houses of Parliament to celebrate a milestone for Southend. Angharad Kolator Baldwin reports…

Earlier this year, Southend-on-Sea was named as the Alternative City of Culture 2017. For family-run jewellery business C J Vinten, run by Gem-A student Lance Vinten and his sister Lily Vinten, this honour resulted in a unique opportunity to attend the Houses of Parliament.

Lily and Lance Vinten at Houses of Parliament
Lance and Lily Vinten in the Houses of Parliament with the C J Vinten Collection 

C J Vinten was chosen, alongside other local businesses, to represent the eclectic talents of Southend at a special gathering on 11 January. Gem-A was invited to witness this fantastic event, but also to learn more about the diverse talent that helped Southend earn the accolade.

Lance Vinten is the son of Christopher Vinten, who established C J Vinten Goldsmiths more than three decades ago. The jeweller, which can be found in Leigh-on-Sea Essex, includes a shop and workshop. When Christopher Vinten retired his children, Lance and Lily, took over the running of the business. 

Before studying at Gem-A, Lance attended the Birmingham School of Jewellery, completing the Jewellery and Silversmithing - HND course. Lily completed her Professional Jewellers’ Diploma with the National Association of Jewellers (NAJ).

Lance started his Gem-A journey with the Gemmology Foundation Online Distance Learning (ODL) course in 2015, swiftly followed by a Gemmology Diploma ODL course. Despite finding the course fascinating, the nature of distance learning made Lance crave conversation with other passionate gemmologists. To remedy this he attends as many of Gem-A’s Gem Central evenings as possible; noting that the “interaction with tutors, professional gemmologists and fellow students” is particularly enlightening.

Read more: Gem Central with Marcus McCallum FGA

When asked what he gained from the Foundation course, he commented that the program gave him a newfound interest in inclusions. He has also found being better at identifying stones, has given him new confidence when interacting with customers. 

This confidence was certainly on display at the Houses of Parliament, where C J Vinten Goldsmiths presented a wonderful collection of jewellery. This included an 18 kt white gold sapphire ring handmade by Lance himself.

Sapphire Ring C J Vinten
18 kt white gold sapphire ring. Image courtesy of C J Vinten

Also on display was a pair of silver dinosaur bone cuff-links and 18 kt white gold drop earrings, each rub-over set with a trillion cut pink sapphire and two brilliant cut diamonds. 

 

Dinosaur Cufflinks C J VintenSilver dinosaur bone cuff-links. Image courtesy of C J Vinten

 

Pink Sapphire Earrings C J Vinten18 kt white gold drop pink sapphire earrings. Image courtesy of C J Vinten

Lance commented: “We brought the pieces that Tom (the head craftsman), my sister Lily and I felt were the most impressive examples of our handmade work. We also wanted to show the range of jewellery that is made here [at CJ Vinten in Southend], to show that you don't need to spend thousands of pounds to get a nice one off piece. It was an honour to be involved in this event and to be invited as guests into the Houses of Parliament.”

For Lily Vinten, the highlight of CJ Vinten’s display was a red spinel and diamond ring, handmade in 18 kt white gold with an 18 kt yellow gold mille grain setting. The oval red spinel is surrounded by two steps of 62 brilliant cut diamonds. She told us: “After seeing many rings featuring vivid red stones in jewellery and fashion magazines and also the rise of Art Deco jewellery, we decided to create this stunning cocktail ring. The 1920s is famous for amazing dresses and jewellery, so with that in mind the craftsman came up with a design that would suit an evening gown.”


Spinel Ring C J VintenThe design process of making the red spinel ring. Image courtesy of C J Vinten

Lance believes continuing his gemmology education, and providing the opportunity for other staff members to continue theirs is “vitally important for the future of the company”. Recently CJ Vinten employed a workshop apprentice, who is already showing good potential, allowing Lance and Tom to pass some designs to her, as well as receive “copious amounts of tea”.

The Mayor of Southend, Cllr Judith McMahon gave a speech at the special event, hailing 2017 as “the Golden age”. She added in reference to Southend: “Art and culture is welcome, where it will flourish and find its natural home.” Looking at the wealth of talent in the room this certainly seems to be true. From folk dancing and confectionary to jewellery, the exhibition showcased it all. 

The Alternative City of Culture could not have come to fruition, without the dedication of Sir David Amess MP. A Member of Parliament for Southend West since 1997, he is determined to secure City Status for the town and propel Southend forwards. At the event he said it was a wonderful opportunity “to celebrate the rich culture and community of Southend”. ■  

The project has a 12-month programme of events arranged including art, sport and performance, making Southend the place to visit this year.

To view more of C J Vinten’s jewellery click here

Interested in attending a Gem Central event? For more information about our upcoming Gem Central events visit the Gem Central page or email events@gem-a.com.

Interested in finding out more about gemmology? Sign-up to one of Gem-A's courses or workshops.

Cover image 18 kt white gold cluster ring, claw set with Trillion cut morganite 1.52 ct, surrounded by Brilliant cut diamonds and further diamonds in split shank, 0.31 ct total, handmade by Lance. Image Courtesy of C J Vinten. 


Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Gem-A tutor Barbara Kolator B.Sc. M.Sc. FGA DGA EG shares some highlights from her recent trip to the Institut de Gemmologie de Madagascar in Antananarivo, which is a proud Gem-A Accredited Teaching Centre (ATC). 

Read more


Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Famous for her ostentatious sense of style, 18th century French Queen Marie Antoinette was back as the centre of attention at Sotheby's in November thanks to the record-breaking sale of her natural pearl and diamond pendant. Here, Beth West FGA DGA EG considers the history behind this fascinating piece. 

Read more


Birthstone Guide: Tanzanite for Those Born in December

Birthstone Guide: Tanzanite for Those Born in December

Looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers the December birthstone tanzanite and how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Journal Digest: Bumble Bee Stone from Indonesia

Journal Digest: Bumble Bee Stone from Indonesia

Guy Lalous ACAM EG delves into an article on Indonesian Bumble Bee Stone (BBS) from The Journal of Gemmology Volume 36, No.3, and presents his edited take on the most essential information, findings and lessons to be learnt. Continue reading here...

Read more


Retail Focus: Beyond the Green

Retail Focus: Beyond the Green

From the Summer 2018 issue of Gems&Jewellery, Gem-A Gemmology Tutor Beth West FGA DGA EG explores Colombian emeralds. 

Read more


Additional Info

Read more...

Inhorgenta 2017 Set to Impress with Gem Forum and Pearl Forum Seminars

Munich-based trade event Inhorgenta has taken its seminar content up a notch for 2017, incorporating a Gem Forum and its fourth annual Pearl Forum on the opening two days of the show.

The international buying event, which officially opens its doors on February 18, will welcome a plethora of speakers, including jewellery expert Joanna Hardy FGA DGA, GemWorld International president, Richard Drucker FGA (honorary), and pearl expert Dr Hubert Bari. 

Alongside its seminar programme, Inhorgenta offers its 'Carat' hall dedicated to gemstone, diamond and pearl wholesalers. The range on offer also includes natural geodes, discs and many other gemstone specimens. 

Assessing the gems on display at Inhorgenta Munich 2016

Inhorgenta 2017 Gemstone Forum schedule – Saturday 18 February 

Once the excitement of the morning has died down, Inhorgenta will present its Gemstone Forum, starting with a talk by Joanna Hardy from 2.30pm-3.30pm titled 'Coloured Gemstones in Jewellery Design Through the Ages'.  

This will be swiftly followed by 'Exploring the World for New Gem Discoveries' – a lecture by gemstone miner, trader and 'modern Indiana Jones', Yianni Melas. 

Melas is perhaps best-known for discovering 'Aquaprase'; a type of chalcedony that had evaded discovery until 2015. The Greek explorer discovered the bluish-green, translucent gem in Africa, although a more precise location remains undisclosed to the public. According to a report by the GIA, who authenticated the material: "Although chalcedony varieties such as chrysoprase and Gem Silica are well known and occur in yellowish green and greenish blue colours, the colour of this material was distinctly different from any African chalcedony examined by GIA to date."

The Gemstone Forum offer will continue with an update on gemstone treatments and deposits by Dr Claudio Millisenda (DGemG), who will conduct his talk at 3.30pm in German. Visitors can, however, benefit from a translation service played through a headset. Finally, the day one schedule will conclude with a talk by Gemworld International president, Richard Drucker FGA (hons), who will discuss 'Pricing Colour: The Methodology and Challenges'.

Any visitors to Munich who return to the show for day two, Sunday February 19, will also have the chance to experience the fourth annual Pearl Forum – a series of talks and seminars that have proved especially popular in recent editions of the trade event. Take a look at the video below to see Dr Laurent Cartier FGA sharing his words of wisdom at the 2016 Pearl Forum...

The theme for the 2017 Pearl Forum focuses on unexpected types of pearls, including finding innovative ways of using pearls in jewellery and creative means to market them. ‘The Rare and Unique World of Natural Pearls’ will be the first talk of the day at 10.30am, led by Dr Hubert Bari. Dr Bari is a graduate of the University of Strasbourg and a lecturer at the National Museum of Natural History in Paris. He has dedicated years to designing and organising exhibitions, and was the first to introduce audio guide systems more than 20-years ago. More recently, Dr Bari orchestrated the Pearls Exhibition, which travelled from Qatar to Tokyo in 2012, and later to London’s Victoria & Albert museum. 

A selection of pearls on display at Inhorgenta Munich 2016

At 11am, Douglas McLaurin, of Cortez Pearls, will discuss pearls from Mexico, followed by a discussion on ‘Pushing the Boundaries of Pearl Design’ by designer Melanie Georgacopoulous. Both of these lectures will be quickly succeeded by ‘Selling Pearls Online: Connecting with the Millennial Market’ – a talk by Pearl Paradise founder, Jeremy Shepherd. 

Read more: Diving into the World of New Zealand Paua Shells

Shepherd founded PearlParadise.com after discovering the world of pearls during his travels around Asia. Today, the digital company with its ‘farm-direct prices’ approach is worth a staggering $20 million, despite very little advertising.

The fourth annual Pearl Forum will conclude with a screening of ‘Power of Pearls’ – a film created by directors Ahbra Perry and Taylor Higgins of On the Reel Productions. The duo has travelled extensively to some of the most remote regions of the earth in order to learn more about pearls. Their film, which uses a combination of underwater, aerial and slow motion footage, will be formally premiered later this year. ■ 

Take a look at the trailer for ‘Power of Pearls’ below… 

Interested in finding out more about gemmology? Sign-up to one of Gem-A's courses or workshops.

If you would like to subscribe to Gems&Jewellery and The Journal of Gemmology please visit Membership.

All photos by Inhorgenta Munich, except where otherwise stated. 


Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Gem-A tutor Barbara Kolator B.Sc. M.Sc. FGA DGA EG shares some highlights from her recent trip to the Institut de Gemmologie de Madagascar in Antananarivo, which is a proud Gem-A Accredited Teaching Centre (ATC). 

Read more


Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Famous for her ostentatious sense of style, 18th century French Queen Marie Antoinette was back as the centre of attention at Sotheby's in November thanks to the record-breaking sale of her natural pearl and diamond pendant. Here, Beth West FGA DGA EG considers the history behind this fascinating piece. 

Read more


Birthstone Guide: Tanzanite for Those Born in December

Birthstone Guide: Tanzanite for Those Born in December

Looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers the December birthstone tanzanite and how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Journal Digest: Bumble Bee Stone from Indonesia

Journal Digest: Bumble Bee Stone from Indonesia

Guy Lalous ACAM EG delves into an article on Indonesian Bumble Bee Stone (BBS) from The Journal of Gemmology Volume 36, No.3, and presents his edited take on the most essential information, findings and lessons to be learnt. Continue reading here...

Read more


Retail Focus: Beyond the Green

Retail Focus: Beyond the Green

From the Summer 2018 issue of Gems&Jewellery, Gem-A Gemmology Tutor Beth West FGA DGA EG explores Colombian emeralds. 

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Additional Info

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A Quick Guide to the Crown Jewels at the Tower of London

Andrew Fellows FGA DGA takes a look some of the myths and legends associated with one of the world’s most famous gem collections, the Crown Jewels.

Foundations were laid for the Tower of London - where the famous Crown Jewels are housed - as early as 1066 by William the Conqueror. Successive monarchs then added to and reinforced the Tower, until, by the late thirteenth century, the general layout seen today was established. The Crown Jewels, the only working collection in Europe, is comprised of over 141 objects, which have been stored securely within the Tower for hundreds of years. It is these that attract hordes of tourists each year.

However, whilst the collection is worth seeing simply for the sheer beauty of the pieces, it is also worth seeing to learn about the captivating stories and histories behind some of the gems.

The Imperial State Crown

The Imperial State Crown - possibly the most well-known individual piece of regalia in the collection - is worn by the monarch at the end of his or her coronation ceremony, and is also used for the State Opening of Parliament. The Crown is such an important piece that it even has its own coach for these important occasions - one that is every bit as ornate as the crown itself. Weighing in at an impressive 3.17 kg, it can only be worn for short periods.

One story says that when George IV was crowned in 1821, he developed a toothache that he blamed on the weight of the crown! The crown contains some of the most important jewels in the Royal Collection, many of which also have the most interesting stories attached to them.

The Black Prince's Ruby

One story that most gemmologists are familiar with is that of the Black Prince's Ruby. This is simultaneously one of the most beautiful and most sinister stones… and one which is also completely misnamed. Although referred to as ruby, this is actually a very large gem-quality red spinel, presented to Edward of Woodstock, a fourteenth century Prince of Wales, Duke of Cornwall, and Prince of Aquitaine, referred to more often as ‘The Black Prince’.

The Imperial State Crown. Copyright Cyril Davenport. Tower of London
The Imperial State Crown. Copyright Cyril Davenport

The gem, which sits in the cross pattée above the Cullinan II at the front of the crown, has a very dark and bloody history. It was first recorded in the fourteenth century as being owned by a Moorish Prince, Abu Said, who attempted to surrender to the conquering forces of Pedro the Cruel. Abu Said was ambushed under a flag of truce and executed with this large spinel being taken from his corpse. This was just the start of the trail of blood, as Pedro himself broke several contracts, before presenting the stone to Prince Edward as a down payment for military assistance. The remainder of the payment was supposed to consist of treasure and jewels, but was never delivered, and eventually Pedro himself was ambushed and stabbed to death by his half-brother.

Read more: Last chance to see the record-breaking Foxfire Diamond at the Smithsonian

The stone was later worn in the battle helmet of Henry V when he went into the Battle of Agincourt in 1415, and allegedly saved his life when he received a blow to the head from an axe - one which destroyed the helmet, but didn't kill Henry. The 'ruby' was recovered from the shattered helmet and remained with Henry V until his death. The same unfortunately cannot be said of Richard III, who also wore the 'ruby' in his battle helmet when he fought at the Battle of Bosworth Field in 1485. Presumably, Richard thought it would protect him and bring him luck, but sadly he was mistaken and died on the battlefield. This same ruby was later used in the crowns of Henry VI, Edward IV and Henry VIII (who wore it in a collar), before being sold by Charles I. It was returned to the monarchy for the crown of Charles II, and was subsequently used for the coronation of George IV.

St Edward's Sapphire

Also in the Imperial State Crown is a sapphire, set in the cross on top of the Crown. Legend has it that this sapphire once resided in the coronation ring of Edward the Confessor, and that one evening he was passing through Westminster when he happened upon a beggar. Having already given away all the money he had on him, he gave the ring to the beggar and thought nothing further of it.

Read more: The history of diamonds in engagement rings

Years later two Englishmen were on a pilgrimage to the Holy Land and, in the middle of a violent storm, saw an old man approaching them. When the old man heard that the two men were English, and that Edward was still King, the old man offered them shelter for the night. When they departed the next morning, the old man revealed himself to be John the Evangelist, and told them that years ago King Edward had given him a ring, which he still had, and gave it to them to return to the King, with a message that he, John, would see the King in Paradise as a reward for his kindness in six months' time. When the two men returned to England, they gave both the ring and the message to King Edward, who immediately prepared for his death. The King died six months later, to be buried with the ring on his finger. Stranger still is the fact that when the tomb was reopened in the twelfth century, the ring was found on a perfectly preserved corpse.

Tower of London at night. Copyright Kjetil Bjørnsrud. Tower of London
Tower of London at night. Copyright Kjetil Bjørnsrud

Whilst some of these stories are merely legend and may or may not be true, what is known as fact is that the Crown Jewels contain some of the best known and largest diamonds in the world, the most famous of which are probably the Koh-i-Noor and the Cullinan.

The Cullinan Diamond

The Cullinan was found at the Premier Mine in South Africa, on the afternoon of 26 January 1905, by the mine superintendent, Captain Frederick Wells. Initially he doubted it was a diamond as it weighed 3106 ct and measured 3 7/8 × 2 1/4 × 2 5/8 inches, well over twice the size of any other diamond found to that date. This was sold to the Transvaal government for £150,000, and two years later the still uncut diamond was presented to King Edward VII on his 66th birthday. Cutting of the stone was a job given to I. J. Asscher and Company, of Amsterdam, who had some experience of cutting large diamonds, although nothing on this scale or value. After three months of consideration, the Cullinan was ready to be cut.

In those days the only way to divide a diamond was by cleaving it - effectively 'hitting' the stone in precise directions to cause the diamond to part along weaker directions, but this had to be done carefully, in order to avoid shattering it. Careful cleaving resulted in nine major 'pieces', and 96 offcuts. Once the whole cutting process was completed, a total of 1063 ct remained.

Read more: Harrods unearths 228.31 ct diamond from its vaults for private sale

The nine major stones, named Cullinan I to Cullinan IX, all reside in the Royal Collection. The majority are set in such a way as to be interchangeable into other pieces of jewellery. Cullinan I, also known as the Star of Africa, is in the Royal Sceptre, and weighs just over 503 ct, making it the largest colourless pearcut diamond in the world. The Cullinan II (the 'Lesser Star of Africa'), is the largest cushioncut diamond in the world, weighing 317 ct, and is set into the front of the Imperial State Crown. It also has two platinum loops on its setting, so that it can be removed and worn alone, as a brooch or pendant, or with the Cullinan I accompanying it.

The Koh-i-Noor Diamond

A second notable diamond exists in the Queen Mother's Crown, this being the Koh-i-Noor, which translates as 'Mountain of Light'. This impressive diamond currently weighs 105.6 ct, having been recut from its original 186 ct for Queen Victoria in 1852.

There is a legend that this stone will bring good luck to any woman who wears it, but a curse to any man! It is said that in 1739 Nadir Shah of Persia conquered the Mogul region, but could find no sign of this rare and fabled diamond, said to be held by the rulers, until one member of the royal court told him of the stone's location. Shah then threw a celebration, and offered to exchange turbans with the conquered leaders as a show of everlasting friendship, knowing that this was the hiding place of the Koh-i-Noor.

The diamond changed hands many times over the coming decades, until in 1850, the Koh-i-Noor finally found its way to England and to Queen Victoria, where it has remained ever since.

Whilst the Crown Jewels are a wonderful piece of English history, they are also shrouded in legend, and are more than just adornments. There are a multitude of stories and histories, all waiting for visitors to uncover. Whether you appreciate them from a gemmological or historical perspective, or simply want to see jewels that most of us will never afford, the Crown Jewels are the perfect way to spend a day in London. ■ 

This article originally appeared in Gems&Jewellery Sept/Oct 2016 / Volume 25 / No. 5 pp. 14-15

Interested in finding out more about gemmology? Sign-up to one of Gem-A's courses or workshops.

If you would like to subscribe to Gems&Jewellery and The Journal of Gemmology please visit Membership.

Cover image the nine major uncut stones split from the rough Cullinan diamond in order of size (largest to smallest).


Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Gem-A tutor Barbara Kolator B.Sc. M.Sc. FGA DGA EG shares some highlights from her recent trip to the Institut de Gemmologie de Madagascar in Antananarivo, which is a proud Gem-A Accredited Teaching Centre (ATC). 

Read more


Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Famous for her ostentatious sense of style, 18th century French Queen Marie Antoinette was back as the centre of attention at Sotheby's in November thanks to the record-breaking sale of her natural pearl and diamond pendant. Here, Beth West FGA DGA EG considers the history behind this fascinating piece. 

Read more


Birthstone Guide: Tanzanite for Those Born in December

Birthstone Guide: Tanzanite for Those Born in December

Looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers the December birthstone tanzanite and how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Journal Digest: Bumble Bee Stone from Indonesia

Journal Digest: Bumble Bee Stone from Indonesia

Guy Lalous ACAM EG delves into an article on Indonesian Bumble Bee Stone (BBS) from The Journal of Gemmology Volume 36, No.3, and presents his edited take on the most essential information, findings and lessons to be learnt. Continue reading here...

Read more


Retail Focus: Beyond the Green

Retail Focus: Beyond the Green

From the Summer 2018 issue of Gems&Jewellery, Gem-A Gemmology Tutor Beth West FGA DGA EG explores Colombian emeralds. 

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Additional Info

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Reconstructed Amber Broken Down

This article by Guy Lalous ACAM EG summarises a technical article from The Journal of Gemmology discussing the identification criteria for early (pre 2009) and current (post 2009) reconstructed amber, based on documented samples at the National Gemstone Testing Center (NGTC) in Beijing.

Newer amber material presents a serious identification challenge for gemmological laboratories. By comparing the structure of reconstructed amber with that of natural amber, is it possible to identify it? 

Read more: Diving into the World of New Zealand Paua Shells

Amber is formed from fossilised tree resin, but may have inclusions of animals, insects, plant debris, minerals, liquids and gases. The fossilisation process involves a progressive oxidation, where the original organic compounds gains oxygen, and polymerisation, which is an addition reaction where two or more molecules join together. This process produces oxygenated hydrocarbons, which are organic compounds made of oxygen, carbon and hydrogen atoms.

What is reconstructed amber?

Reconstructed amber consists of small amber fragments or scraps that have been reformed into larger pieces under heat and pressure. It is commonly manufactured from pieces of Baltic material. According to the process used, two main types of reconstructed amber exist:

Type 1 made without the addition of any substances to the amber fragments.

Type 2 which contains foreign substances (e.g. natural or artificial resins) that are added to make the material more solid and durable.  

Early reconstructed type 2 amber
13 mm diameter beads made of reconstructed amber containing foreign substances

What is Baltic amber? 

Baltic amber is fossil resin from coniferous trees. Baltic amber, also called succinate, contains 3-8% succinic acid. It was formed about 44 million years ago and today it is found in forests in Lithuania, Russia and Poland, where it is mined and exported in large quantities. The origin is confirmed by the presence of a ‘Baltic Shoulder’ in the fourier transform infrared spectroscopy (FTIR) spectra. Infra-red (IR) spectroscopy is the most effective scientific method for identifying fossil resins. 

What are the identification features of heated amber?

Heat-enhanced amber contains brownish flow lines. These flow lines result from the oxidation of pre-existing cracks that are healed during enhancement at low temperature and pressure, to solidify the raw material and to help avoid future cracking. The heating process will change the refractive index (RI) and infrared spectral readings. The higher the temperature used, the higher the RI will be, up to a maximum of 1.60. Exposure to greater temperatures may also alter some of the FTIR features: the ~1735 cm−1 absorption band shifts to down to 1716 cm−1, and the ~1157 cm−1 absorption band moves up to 1175 cm−1. The variations in RI and infrared spectra indicate that an amber specimen has been heated, but they do not provide conclusive evidence of reconstruction. 

Read more: Getting to Grips with GemTof Technology

When there is little or no foreign substance present, the FTIR spectra of reconstructed amber looks almost identical to that of natural amber, and additional examinations using a microscope, polariscope and UV lamp should be performed to make the proper identification. Most samples encountered at NGTC are type 1 reconstructed amber.  

What are the identification features of early reconstructed amber? 

Early reconstructed amber involved the use of relatively high temperature and pressure conditions in air. It is relatively easy to identify. The material displays a relatively dark body colour, poor transparency with a muddy-looking interior, and a diagnostic fragmental or mosaic structure (known as ‘blood streak’ in Chinese as it resembles blood vessels). The boundaries between fragments have oxidised (darker) edges that appear translucent brown or red. In addition to this some early-stage reconstructed amber may display uneven surface lustre, due to different hardness characteristics of the partially melted amber fragments.  

mosaic structure early reconstructed amber Heat enhanced amber

A 3-D mosaic structure in early reconstructed amber shows a network of angular boundaries that completely enclose the fragments. Below: By contrast, heat-enhanced amber displays brownish red flow lines that do not interconnect. Magnification 10x

How can you differentiate between natural and reconstructed amber?

Natural amber is amorphous and often shows anomalous double refraction in the polariscope, sometimes displaying snake-like, wavy or patchy extinction patterns. By contrast, early-stage reconstructed amber shows patchy grainy extinction, with clear grain boundaries and often exhibits interference colours. 

Natural amber usually displays even fluorescence, viewed with a UV lamp or in a DiamondView instrument. While darker-coloured early-stage reconstructed amber may not show diagnostic fluorescence, pale-coloured material commonly shows uneven luminescence with a fragmental or granular structure.  

What are the identification features of current-stage reconstructed amber?

Current-stage reconstructed amber is manufactured under relatively higher temperature and pressure in an oxygen-free environment. It is often subjected to post-processing treatments that are designed to conceal identifying features. These include inducing internal and surface cracks (by heating and cooling), polishing with coarse grit to create a matt appearance, darkening the surface colour (by baking), carving complex patterns and applying coloured coatings. Microscopic observation reveals that finer grains are typically used as raw material for current reconstructed amber. Usually showing a more subtle and fine-grained fragmental structure consisting of areas of pale colour are enclosed by dot-like edges. The dark-coloured grain boundaries are nearly absent and can only be seen with careful observation, the ‘blood streak’ structure is not apparent. The post processing treatments obscure the features observed with the polariscope, UV lamp or the DiamondView. 

opaque reconstructed amber

natural amber and reconstructed amber

Above: Viewed with a strong transmitted light source, this opaque reconstructed amber bead exhibits no ‘blood streak’ structure, although the angular fragments are still apparent. Below: Two beads in an amber bracelet consist of natural amber (left) and current reconstructed amber (right) display fuzzy grain boundaries with no ‘blood streak’ structure. The presence of small grains with angular boundaries is the key identification factor for the reconstructed amber bead. Magnification 16x (left) and 12.5x (right)

Conclusion

The most effective method to identify reconstructed amber from natural amber is microscopy, to observe the internal microstructure. The Polariscope and UV Fluorescence are useful auxiliary methods but cannot be used to reliably separate current reconstructed natural amber. 

This is a summary of an article that originally appeared in The Journal of Gemmology entitled ‘Identification of Reconstructed Amber from Different Periods’ by Haibo Li, Jie Liang, Taijin Lu, Jun Zhang and Jun Zhou 2016/Volume 35/ No. 4 pp. 320-328

Interested in finding out more about gemmology? Sign-up to one of Gem-A's courses or workshops.

If you would like to subscribe to Gems&Jewellery and The Journal of Gemmology please visit Membership.

Cover image Flanky internal cracks, eviddence of post processing heat treatment in current reconstructed amber. All photos by H. Li


Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Gem-A tutor Barbara Kolator B.Sc. M.Sc. FGA DGA EG shares some highlights from her recent trip to the Institut de Gemmologie de Madagascar in Antananarivo, which is a proud Gem-A Accredited Teaching Centre (ATC). 

Read more


Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Famous for her ostentatious sense of style, 18th century French Queen Marie Antoinette was back as the centre of attention at Sotheby's in November thanks to the record-breaking sale of her natural pearl and diamond pendant. Here, Beth West FGA DGA EG considers the history behind this fascinating piece. 

Read more


Birthstone Guide: Tanzanite for Those Born in December

Birthstone Guide: Tanzanite for Those Born in December

Looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers the December birthstone tanzanite and how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Journal Digest: Bumble Bee Stone from Indonesia

Journal Digest: Bumble Bee Stone from Indonesia

Guy Lalous ACAM EG delves into an article on Indonesian Bumble Bee Stone (BBS) from The Journal of Gemmology Volume 36, No.3, and presents his edited take on the most essential information, findings and lessons to be learnt. Continue reading here...

Read more


Retail Focus: Beyond the Green

Retail Focus: Beyond the Green

From the Summer 2018 issue of Gems&Jewellery, Gem-A Gemmology Tutor Beth West FGA DGA EG explores Colombian emeralds. 

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Additional Info

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Field Trip: Screening for Tourmaline at the Oceanview Mine, California

Claire Mitchell FGA DGA takes a hands-on look at the Oceanview Mine, in the Pala mining district in California, USA.

Oceanview Mine is situated 2.5 miles northeast of Pala, on the northeastern slope of Chief Mountain, a short, scenic drive from Pala, California. Visitors to the area pass through landscapes bedecked with nurseries growing a multitude of produce and plants; turning off the main highway you pass through beautiful orange groves, finally reaching the dirt track which takes you up to the mine. 

Famous mines in this area also include the Tourmaline Queen, famous for its 'blue cap pocket' tourmaline, and Pala Chief Mine, famous for its kunzite. The area has been a source of gem materials since the 1870s; with its most active period being between 1900 and 1922. 

Claim was first made to the Oceanview deposit in 1907 by Frank A. Salmons. Since then, ownership has passed through several hands during its lifetime, and the mine is now owned by Jeff Swanger, who acts as CEO, owner and operator of Oceanview Gem Mine LLC. In its lifetime the mine has produced some of the best morganite specimens ever recovered in North America, as well as exceptional tourmaline and kunzite, with additional minerals of lepidolite, mica, apatite, quartz and feldspars.

Black Tourmaline from Oceanview Mine.
Black Tourmaline from Oceanview Mine. Sorted by Claire Mitchell

Today the Oceanview Mine is the only actively working underground mine in this district. The mine is also open to the public for a fee-for-dig, dump screening - which I gleefully attended in April 2016.

Read more: Last Chance to See the Record-Breaking Foxfire Diamond at the Smithsonian

Two things first struck me when I first arrived: firstly, the amazing view from the top of the site, and secondly the beautiful, perfumed smell of wildflowers in the air.

The set up for the mining experience was simple: there was a large dump pile of material which had been taken out of the mine by excavator, around which the screening equipment was situated.

Dump pile and sorting trays at Oceanview mine
Dump pile and sorting trays at Oceanview mine

When I first arrived I was allocated a position and screening equipment, and after a safety briefing I was instructed on the most efficient and proficient technique for screening the material. We were given four hours to work the pile; so using a bucket and small shovel I collected a full bucket and returned to my workstation. Two large wooden heavy wire screens allow you to 'sift' the material - the first screen (with the larger mesh) sits atop the second screen with a smaller mesh.

Material collected from the pile is placed in the top mesh, the smaller material of which then passes through to the second mesh. Any larger pieces in the top mesh are then washed and checked for gem-quality material and discarded or kept as required.

Claire Mitchell FGA DGA sifting and sorting the material at Oceanview Mine
Claire Mitchell FGA DGA sifting and sorting the material at Oceanview Mine

The material in the second screen is then washed and checked for gem-quality material. It is thrilling seeing glimmers of colour or good crystal form.

Read more: Getting to Grips with GemTOF Technology

After four hours of happy and productive sifting, it was time to assess the fruits of the day's labours. These included tourmaline (pink, green and black, or 'schorl'), mica, quartz, garnet and beryl. Sadly I had to leave behind some of the larger pieces such as the tourmalines in matrix due to weight restrictions on my baggage, which, whilst not 'gemmy', were still very interesting pieces.

Tourmalines in matrix at Oceanview mine
Tourmalines in matrix

Visitors can also experience a jeep tour of Chief Mountain, which not only offers some breath-taking views but also allows you to catch a glimpse of the active mine entrance and prospects, as well as views of other famous mines in the area. At the edge of the ridge you can see the Tourmaline Queen Mountain, and in the distance you can just about see other former mine workings. 

There is truly nothing better than digging for gem materials - it's a great visit, for both the experience and for the introduction into the techniques in sorting by this method. I thoroughly recommend this to anyone visiting the area - a bonus is the fantastic weather and beautiful countryside whilst there.      

This article originally appeared in Gems&Jewellery July/August 2016 / Volume 25 / No. 4 pp. 14-15

Interested in finding out more about gemmology? Sign-up to one of Gem-A's courses or workshops.

If you would like to subscribe to Gems&Jewellery and The Journal of Gemmology please visit Membership.

Cover Image coloured tourmaline. All photos by Claire Mitchell. 


Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Gem-A tutor Barbara Kolator B.Sc. M.Sc. FGA DGA EG shares some highlights from her recent trip to the Institut de Gemmologie de Madagascar in Antananarivo, which is a proud Gem-A Accredited Teaching Centre (ATC). 

Read more


Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Famous for her ostentatious sense of style, 18th century French Queen Marie Antoinette was back as the centre of attention at Sotheby's in November thanks to the record-breaking sale of her natural pearl and diamond pendant. Here, Beth West FGA DGA EG considers the history behind this fascinating piece. 

Read more


Birthstone Guide: Tanzanite for Those Born in December

Birthstone Guide: Tanzanite for Those Born in December

Looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers the December birthstone tanzanite and how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Journal Digest: Bumble Bee Stone from Indonesia

Journal Digest: Bumble Bee Stone from Indonesia

Guy Lalous ACAM EG delves into an article on Indonesian Bumble Bee Stone (BBS) from The Journal of Gemmology Volume 36, No.3, and presents his edited take on the most essential information, findings and lessons to be learnt. Continue reading here...

Read more


Retail Focus: Beyond the Green

Retail Focus: Beyond the Green

From the Summer 2018 issue of Gems&Jewellery, Gem-A Gemmology Tutor Beth West FGA DGA EG explores Colombian emeralds. 

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Additional Info

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Vivid Purple and Violet Diamonds Shine in 'Rare Brilliance' Showcase

A breath-taking array of rare, fancy colour diamonds is on display now at The Natural History Museum of Los Angeles County (NHMLA).

The 'Diamonds: Rare Brilliance' exhibit features diamonds never seen before in the United States, including the largest violet diamond ever discovered in Australia’s Argyle Mine. Anyone with a passion for diamonds is encouraged to view the full collection before it is taken out of public view on March 19, 2017.

Included in the collection are three exceptionally rare fancy coloured diamonds: a 30.3 ct Fancy Intense Pink, a 2.83 ct Fancy Deep Grayish Bluish Violet and a 1.64 ct Fancy Vivid Purple diamond, all loaned by L. J. West - a New York-based diamond house.

The Juliet Diamond

'Diamonds: Rare Brilliance' is centred round a 30.03 ct Fancy Intense Pink, also known as The Juliet Diamond, which was cut from a 90 ct rough found in South Africa. The Juliet Diamond - romantically named after Romeo and Juliet - is similar to the 34.65 ct, cushion-cut Fancy Intense Pink Princie Diamond, which was discovered 300 years ago in the Golconda Mines. It was sold by Christie’s in April 2013 for $39.3 million.

Rather than being presented on its own, the Juliet is mounted in an impressive necklace set with 98.70 ct of round brilliant, pear and marquise-cut colourless diamonds of E and F colour and VVS clarity.

Juliet Pink Necklace. Image Courtesy of Brian Lazar. NHM LA
Juliet Pink Diamond - set in a necklace with marquise, pear and round-cut shape white diamonds. Image Courtesy of Brian Lazar

 

The Argyle Violet Diamond

Named after its place of discovery - the Argyle Diamond Mine in Western Australia - the Argyle Violet is a sensational and almost impossibly rare 2.83 ct Fancy Deep Grayish Bluish Violet gem. Its hypnotic colour was the star attraction at the 2016 Argyle Pink Diamonds Tender, which offered an invite-only look at this magnificent diamond.

The Argyle Violet was expertly cut from a 9.17 ct rough, with incredible skill used to harness the colour to its maximum potential.

Argyle Violet Ring. Image courtesy of Aaron Celestian. NHM of LA
Argyle Violet Ring. Image courtesy of Aaron Celestian

 

The Victorian Orchid Vivid Purple

The 1.64 ct, cushion-cut, Fancy Vivid Purple 'Victorian Orchid' diamond is considered one of the rarest in the world thanks to its unique colourway and SI2 clarity. It is displayed mounted in the centre of a flower-like platinum ring.

Victorian Orchid Vivid Purple. Image Courtesy of Aaron Celestian. NHM LA
Victorian Orchid Vivid Purple. Image Courtesy of Aaron Celestian

 

The Rainbow Diamond Necklace

'Diamonds: Rare Brilliance' also features the showstopping Rainbow Necklace set with 88 fancy radiant-cut, coloured diamonds in a range of hues (shown in cover image). The total diamond weight is 35.93 ct. According to L. J. West, it took five years to source all of the necessary diamonds for the piece and then complete the assembly process. 

All of these incredible diamonds will be available to view in the NHMLA’s 6,000 sq ft Gem and Mineral Hall until March 19, 2017. To find out more please click here. ■

NHMLA Gem and Mineral Hall. Image Courtesy of NHMLA
NHMLA Gem and Mineral Hall. Image Courtesy of NHMLA

Interested in finding out more about diamonds? Sign-up to one of Gem-A's diamond courses or workshops.

If you would like to subscribe to Gems&Jewellery and The Journal of Gemmology please visit Membership.

Cover image Rainbow Diamond Necklace. Image courtesy of Brian Lazar.


Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Gem-A tutor Barbara Kolator B.Sc. M.Sc. FGA DGA EG shares some highlights from her recent trip to the Institut de Gemmologie de Madagascar in Antananarivo, which is a proud Gem-A Accredited Teaching Centre (ATC). 

Read more


Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Famous for her ostentatious sense of style, 18th century French Queen Marie Antoinette was back as the centre of attention at Sotheby's in November thanks to the record-breaking sale of her natural pearl and diamond pendant. Here, Beth West FGA DGA EG considers the history behind this fascinating piece. 

Read more


Birthstone Guide: Tanzanite for Those Born in December

Birthstone Guide: Tanzanite for Those Born in December

Looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers the December birthstone tanzanite and how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Journal Digest: Bumble Bee Stone from Indonesia

Journal Digest: Bumble Bee Stone from Indonesia

Guy Lalous ACAM EG delves into an article on Indonesian Bumble Bee Stone (BBS) from The Journal of Gemmology Volume 36, No.3, and presents his edited take on the most essential information, findings and lessons to be learnt. Continue reading here...

Read more


Retail Focus: Beyond the Green

Retail Focus: Beyond the Green

From the Summer 2018 issue of Gems&Jewellery, Gem-A Gemmology Tutor Beth West FGA DGA EG explores Colombian emeralds. 

Read more


Additional Info

Read more...

The University of Nantes Announces DUG Diploma to Be Taught in English for First Time

French gemmological education centre, the University of Nantes, has announced plans to teach its advanced gemmology program, also known as DUG (Diplôme d'Université de Gemmologie), in English for the first time. 

Teaching will be done in English from November 6 to December 8, 2017, followed by examinations in spring 2018 to offer convenience for international students. 

Based in the Upper Brittany region of Western France, the University of Nantes offers a number of courses with an emphasis on nurturing laboratory gemmologists. Students on the DUG Diploma will learn how to use lab tools, such as infrared, Raman and UV-visible spectrometers and a scanning electron microscope (SEM), under the tutelage of expert gemmologists. 

To complete the course, students are required to submit a short scientific study on a gemmological topic of their choice. This is then followed by an oral presentation, giving students the chance to discuss their work in more detail. 

Those interested in finding out more about the course are encouraged to contact Emmanuel Fritsch FGA (Hons) (emmanuel.fritsch@cnrs-imn.fr) and Benjamin Rondeau (benjamin.rondeau@univ-nantes.fr). 

Find out more about the history of Gem-A here

Interested in finding out more about gemmology? Sign-up to one of Gem-A's courses or workshops.


Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Gem-A tutor Barbara Kolator B.Sc. M.Sc. FGA DGA EG shares some highlights from her recent trip to the Institut de Gemmologie de Madagascar in Antananarivo, which is a proud Gem-A Accredited Teaching Centre (ATC). 

Read more


Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Famous for her ostentatious sense of style, 18th century French Queen Marie Antoinette was back as the centre of attention at Sotheby's in November thanks to the record-breaking sale of her natural pearl and diamond pendant. Here, Beth West FGA DGA EG considers the history behind this fascinating piece. 

Read more


Birthstone Guide: Tanzanite for Those Born in December

Birthstone Guide: Tanzanite for Those Born in December

Looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers the December birthstone tanzanite and how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Journal Digest: Bumble Bee Stone from Indonesia

Journal Digest: Bumble Bee Stone from Indonesia

Guy Lalous ACAM EG delves into an article on Indonesian Bumble Bee Stone (BBS) from The Journal of Gemmology Volume 36, No.3, and presents his edited take on the most essential information, findings and lessons to be learnt. Continue reading here...

Read more


Retail Focus: Beyond the Green

Retail Focus: Beyond the Green

From the Summer 2018 issue of Gems&Jewellery, Gem-A Gemmology Tutor Beth West FGA DGA EG explores Colombian emeralds. 

Read more


 

 

Additional Info

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Birthstones Guide: The Meaning Behind February Gemstone Amethyst

Julia Griffith FGA DGA EG, Gemmology and Diamond Tutor at Gem-A, introduces amethyst. Writing about the history of this beautiful stone and informing us about its gemmological properties...

 The February-born shall find

Sincerity and peace of mind,

Freedom from passion and from care,

If they, the amethyst will wear.

 

Let her an amethyst but cherish well,

And strife and care can never her dwell.

                                                  Anon. 

February's birthstone amethyst is one of the most recognised gemstones on the market. Many are familiar with the lore and appearance of this purple gemstone...more so than the hundreds of other gemstones that are offered within our trade. 

Amethyst is the purple variety of quartz and out of all of the quartz gemstones ranks at the top for desirability and value. Amethysts are pale pinkish-violet to deep reddish-purple in hue and are most often found as faceted gems, cabochons or carvings. Many rough forms are also used within jewellery including single crystals, clusters or slices of crystal-lined cavities known as geodes. The most prized amethysts are known as Russian or Siberian Amethyst, named after the fine specimens found in these localities. These have a good clarity and rich purple colouration with flashes of red.

Amethyst DreamscapeTM 53.37 ct cut by John Dyer & CO. Photo by Lydia Dyer
Amethyst DreamscapeTM 53.37 ct cut by John Dyer & CO. Photo by Lydia Dyer

Read more: An Exclusive Interview with Gem Cutter John Dyer

Historically, amethyst was kept as a talisman as it was believed to counteract the effects of alcohol. The word amethyst derives from the ancient Greek amethustos, which translates plainly to not drunk.  

This mystical belief in amethyst in keeping one sober extends back to 320 BC to the poet Asclepiades of Samos, likely inspired by the wine-like colours of this gem. People believed that wearing an amethyst would save them from inebriation. The more affluent indulgers would sip from carved amethyst goblets or add powdered amethyst into their wine to keep their sobriety. This mystical power was argued as false by Pliny the Elder in the first century AD, however the belief continued for centuries to come.

Read more: From Elizabeth I to Elizabeth Taylor with John Benjamin FGA DGA

Inspired by the amethysts association to wine, the French poet Remy Belleau created a myth in the sixteenth century explaining how the stone came into existence.

The poem speaks of Bacchus, the Greek God of wine and beautiful maiden named Amethystos, who refused the advances of Bacchus and prayed to the Goddess Diana to keep her chaste. To protect her, Diana transformed Amethystos into white crystal quartz. In frustration, Bacchus poured his wine over the crystals, dyeing them purple forevermore. 

The belief that amethyst is one of the worlds more precious gems can be linked back to antiquity. Amethyst was one of the twelve gemstones that were mounted in the Priestly Breastplate, cited in the Book of Exodus. It is from these twelve gemstones that the birthstones have their roots. Christianity has used amethyst historically within the Episcopal rings of Bishops and other clergy to represent abstinence from alcohol. 

Within the middle ages, amethyst became a symbol of royalty and the rich purple of amethyst can be found within regal wardrobes and jewels across the world. A large domed amethyst can be found sitting atop the large Cullinan I diamond within the Imperial Sceptre with Cross in our British Crown Jewels. 

The amethyst was considered a cardinal, or most precious, gem and was historically acknowledged in high regard among the diamond, ruby, emerald and sapphire. Cardinal gems held a value above all others due to their beauty and rarity. An abundant source of amethyst was found in Brazil in the eighteenth century and nowadays amethyst is widely accessible and ready to be enjoyed in all its regal beauty by gem and jewellery lovers worldwide. 

Bentley and Skinner Amethyst Bracelet
Bentley and Skinner Amethyst Bracelet. Image courtesy of Bentley and Skinner

This article was written by Gem-A for the January/ February 2017 issue of The Jeweller - The magazine of the National Association of Jewellers

Interested in finding out more about gemmology? Sign-up to one of Gem-A's courses or workshops.

Cover Image quartz amethyst rough crystal from the Gem-A archive. 


Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Gem-A tutor Barbara Kolator B.Sc. M.Sc. FGA DGA EG shares some highlights from her recent trip to the Institut de Gemmologie de Madagascar in Antananarivo, which is a proud Gem-A Accredited Teaching Centre (ATC). 

Read more


Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Famous for her ostentatious sense of style, 18th century French Queen Marie Antoinette was back as the centre of attention at Sotheby's in November thanks to the record-breaking sale of her natural pearl and diamond pendant. Here, Beth West FGA DGA EG considers the history behind this fascinating piece. 

Read more


Birthstone Guide: Tanzanite for Those Born in December

Birthstone Guide: Tanzanite for Those Born in December

Looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers the December birthstone tanzanite and how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Journal Digest: Bumble Bee Stone from Indonesia

Journal Digest: Bumble Bee Stone from Indonesia

Guy Lalous ACAM EG delves into an article on Indonesian Bumble Bee Stone (BBS) from The Journal of Gemmology Volume 36, No.3, and presents his edited take on the most essential information, findings and lessons to be learnt. Continue reading here...

Read more


Retail Focus: Beyond the Green

Retail Focus: Beyond the Green

From the Summer 2018 issue of Gems&Jewellery, Gem-A Gemmology Tutor Beth West FGA DGA EG explores Colombian emeralds. 

Read more


Additional Info

Read more...

Gem-A to Display Historic Instruments at 'Somewhere In The Rainbow' Tucson Exhibit

Gem-A has been invited to take part in a new exhibition of gemstones and gemmology in collaboration with Somewhere In The Rainbow and the University of Arizona Mineral Museum.

The 'Modern Gem and Jewelry Collection' exhibit will open at the Flandrau Science Center & Planetarium in Tucson, on Wednesday 1 February. Visitors will encounter exceptional gemstones from the 'Somewhere In The Rainbow Modern Gem and Jewelry Collection' - a broad selection of gemstones and specimens used to promote education and enjoyment of fine coloured gems to museums, galleries and institutions.

Fluorescent Gems: Natural coloured diamonds laid out in UofA logo by Sean Milliner
Fluorescent Gems: Natural coloured diamonds laid out in U of A logo by Sean Milliner

Read more: Inside the World of Photomicrographer Danny Sanchez

As part of the exhibition, Gem-A will display historic tools used throughout the ages by practicing gemmologists, including a spectroscope, refractometer, microscope and a Chelsea Colour Filter. The archival items on display will range in date from the early 1900s (although many are thought to be much older) through to the present day.

Highlights include the personal spectroscope of one of Gem-A’s founding fathers, Basil W. Anderson, and a special QR link to download ‘The Herbert Smith Refractometer’ - a publication written in 1907 by British mineralogist George Frederick Herbert Smith.

The exhibit will feature the work of 20 lapidary artists and designers, all of whom have won the coveted Spectrum Award from the American Gem Trade Association.

Read more: An Exclusive Interview with Gem Cutter John Dyer

A particular highlight of the collection is the 'Buddha Blue' – a sapphire faceted in 1400-1500 AD. 

The Buddha Blue Ceylon Sapphire Somewhere In The Rainbow
The Buddha Blue Ceylon Sapphire featured in the 'Somewhere In The Rainbow Gem and Jewelry Collection'

It was this particular specimen that inspired Somewhere In The Rainbow curator, Shelly Sergent, to invite eleven of today’s most inspiring gem-cutters to take part in the exhibition and bring their own style of gem cutting and faceting to Tucson.

Read more: Gem Central With Gem Dealer Marcus McCallum

Sergent adds: "We are thrilled for this collaboration of educational forces in the mineral, gemstone and jewelry world to be experienced and enjoyed. This will be the first time that the Somewhere In The Rainbow Collection will be available to this extent as an educational exhibition and we are honored to share it with University of Arizona and all who visit."

Somewhere In The Rainbow curator Shelly Sergent
Somewhere In The Rainbow curator Shelly Sergent

'A Modern Gem and Jewelry Collection' will be available to view from 1 February through to 15 January 2018, with paid admission to the Flandrau Science Center & Planetarium. ■

If you would like more information about this exhibit, please contact Shelly Sergent. shelly@somewhereintherainbow.com

Interested in finding out more about gemmology? Sign-up to one of Gem-A's courses or workshops.

If you would like to subscribe to Gems&Jewellery and The Journal of Gemmology please visit Membership.

All images courtesy of the Somewhere In The Rainbow Facebook page


Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Gem-A tutor Barbara Kolator B.Sc. M.Sc. FGA DGA EG shares some highlights from her recent trip to the Institut de Gemmologie de Madagascar in Antananarivo, which is a proud Gem-A Accredited Teaching Centre (ATC). 

Read more


Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Famous for her ostentatious sense of style, 18th century French Queen Marie Antoinette was back as the centre of attention at Sotheby's in November thanks to the record-breaking sale of her natural pearl and diamond pendant. Here, Beth West FGA DGA EG considers the history behind this fascinating piece. 

Read more


Birthstone Guide: Tanzanite for Those Born in December

Birthstone Guide: Tanzanite for Those Born in December

Looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers the December birthstone tanzanite and how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Journal Digest: Bumble Bee Stone from Indonesia

Journal Digest: Bumble Bee Stone from Indonesia

Guy Lalous ACAM EG delves into an article on Indonesian Bumble Bee Stone (BBS) from The Journal of Gemmology Volume 36, No.3, and presents his edited take on the most essential information, findings and lessons to be learnt. Continue reading here...

Read more


Retail Focus: Beyond the Green

Retail Focus: Beyond the Green

From the Summer 2018 issue of Gems&Jewellery, Gem-A Gemmology Tutor Beth West FGA DGA EG explores Colombian emeralds. 

Read more


Additional Info

Read more...

An Interview with Dr Jeffrey Post of the Smithsonian Institution

Claire Mitchell FGA DGA talks to Dr Jeffrey Post, chairman of the Department of Mineral Sciences and curator of the National Gem and Mineral Collection at the Smithsonian Institution, about advanced gem testing, the Hope diamond and the importance of donations to the museum.

Dr Jeffrey Post with an assortment of beryls, a tanzanite and an amethyst. Interview with Dr Jeffrey Post.
Dr Jeffrey Post with an assortment of beryls, a tanzanite and an amethyst

Q. Moving forward, how important do you feel advanced testing will be?

I think it's getting there - a lot has changed in the last 10-15 years, particularly when you look at the kinds of sophisticated research instruments that the various gem labs have now. These days you’ve got pretty smart scientists out there trying to figure out ways to treat and enhance stones, so it takes pretty smart scientists and good instrumentation to be able to detect these treatments and enhancements. Nowadays there are labs all around the world that are treating stones - sometimes you don't find out about certain treatments until quite a bit later - so we are in an ‘arms race’ of sorts. It's getting to be fairly sophisticated material science - the kinds of techniques that are being applied are ones that are not always easy to detect, and ones that we would never have imagined that could be done. 

Read more: Getting to Grips with GemTOF Technology

I and many others have made the argument for a long time that we need well-trained scientists working in some of these labs, because the nature and sophistication of what is being done is dealing in the scientific. I think it’s a shame that there isn't a really clear path for someone to pursue research in science that will be directly relevant to gems. 

However, GIA - along with a couple of other groups - have tried to get together some funding to hire post-doctorates to work on gem-related projects, and have provided hands-on training to people that have good backgrounds in chemistry, physics and material science. It's clearly a step in the right direction - in the end you get someone who has that scientific background, but who also has some experience working on gem materials and who has been introduced to the gem world.

I think that the gem industry has some responsibility to try to help fund more of the kinds of research that needs to be done, research which will ultimately benefit the industry. Look at beryllium diffusion treatment, for example. That was something that no one ever expected - who would of thought of diffusing beryllium into corundum to change its colour - it's a pretty sophisticated treatment that took some research to figure out and understand, and then to develop a way to identify it. The trade were actually behind on that process by several years before it was finally cracked. 

It should be thought of as a much longer term investment - thinking about the health of the industry. For the good of all of us we need to figure out ways to be sure that we are staying up to date with technology, research and developments in related scientific fields. 

Q. The Smithsonian carried out advanced testing on the Hope diamond. It was reported that the type of instrumentation that was used created a very tiny hole in the diamond - did it? Was it hard to make the decision to test it in that way?

I hate to say it but it did. The key words here are that the hole was very, very, very tiny - if you look at it under a microscope you still can't see it. However, the decision to test in that way wasn't hard, not once I knew what the technique entailed. We had a pretty good understanding of what we were doing, what the test would involve and how the diamond would respond to it. We have a saying at the Smithsonian, that every specimen in the collection is available for research because ultimately, why are we keeping these things if we are not learning from them?

The Hope diamond is a very rare, blue diamond that is a piece of the earth. We use minerals and crystals to learn something about the earth - the Hope diamond has its own story to tell us about how it was formed, where it came from and how it is different from other diamonds, so I think that the fact that we have it in the collection means that it is available for us to study.

The Hope diamond in the Time-of-Flight-SIMS instrument. Image courtesy of Jeffrey Post. Interview
The Hope diamond in the Time-of-Flight-SIMS instrument. Image courtesy of Jeffrey Post

Read more: Harrods Unearths 228.31 ct Diamond from its Vaults for Private Sale

It wasn't just me it was a measured and thoroughly assessed decision. All the way through the tests we kept a close eye on things and made sure that it was working the way we thought it would, and so yes, we knocked a few billion atoms out of there, but no one is going to miss those few billion atoms. 

In the end we learned a fair bit of information about the diamond. We got a lot of publicity after we did that experiment and I think part of the reason for that was that people never thought about the Hope diamond as anything other than a ‘cursed’ gemstone worth a lot of money, so I think for many it was an eye-opener to think of it as something that is worth studying. The fact that it stays in the collection means that we can continue studying it.  

The instrument we use is the Time-of-Flight Secondary Ion Mass Spectrometer (ToF-SIMS) - 10-15 years ago we would never have imagined being able to use such an instrument or for somebody to have one in their department, so who knows, 10-15 years from now what other instrumentation will come along? What other options for testing will we have access to, that are equally non-destructive? It's therefore nice to know that we can go back and continue to try and pull a few little pieces of information from the item and continue to learn its secrets.  

Q. How important is the private sector to the purchase of acquisitions?

It's absolutely critical as the Smithsonian is a public-private partnership. We end up depending very heavily on private donations, particularly endowments that people have set up. Some of these go back 100 years whilst some of them are more recent, so one of our goals is that we are always trying to build up our endowments to continue to support the work that we do. 

Typically the collection has grown not from what we have purchased but from what people have given, so the big private partnerships are the donations that people have given us to help build the collection. Sometimes they come in as a large collection of minerals, sometimes as a single piece of jewellery or a single gemstone. The Smithsonian has been around for a long time (by USA standards, anyway) and so if we continue to accumulate at a steady rate the collection will grow to an even bigger collection. 

Read more: Last Chance to See the Record-Breaking Foxfire Diamond at the Smithsonian

Luckily we have time on our side; we don't need to get everything right away. One of the great parts of my job is the feeling that you are part of something that has had a long history and will have a long future - it's a cool feeling to be a part of something that has longevity associated with it. It gives you context for the work that you are doing and allows you to relax a little bit and say “I don't need to get that thing this year”, or “I don’t need to sell everything to get that one thing”, because that one thing, even if it goes into another collection now, will still be out there. 

The Dom Pedro Aquamarine, cut from a large crystal mined in Minas Gerais, Brazil. Cut by Bernd Munsteiner and donated by Jane Mitchell and Jeffrey Bland to the Smithsonian in 2011. Photo Credit Don Hurlbert. Image Courtesy of Smithsonian Institution.
The Dom Pedro Aquamarine, from Brazil. Cut by Bernd Munsteiner and donated by Jane Mitchell and Jeffrey Bland to the Smithsonian in 2011. Photo Credit Don Hurlbert. Image Courtesy of Smithsonian Institution.

It helps me to realise that my job never really had a beginning and doesn't really have an end; you are just stepping in as a caretaker of sorts, you keep things going and hopefully you will do some good things that will result in the collection growing.

As the National Museum of the USA we don’t charge, and so there really is a sense that people feel like the museum belongs to them - there is no better situation than one where you're saying “it's your museum, it's your collection, here's what we would like to do.” ■

The full version of this article originally appeared in Gems&Jewellery July/August 2016 / Volume 25 / No. 4 pp. 28-33

Interested in finding out more about gemmology? Sign-up to one of Gem-A's courses or workshops.

If you would like to subscribe to Gems&Jewellery and The Journal of Gemmology please visit Membership.

Cover image the Smithsonian's National Museum of Natural History on the National Mall in Washington, D. C. Copyright Smithsonian Institution


Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Field Trip: A Visit to Gem-A ATC Institut de Gemmologie de Madagascar

Gem-A tutor Barbara Kolator B.Sc. M.Sc. FGA DGA EG shares some highlights from her recent trip to the Institut de Gemmologie de Madagascar in Antananarivo, which is a proud Gem-A Accredited Teaching Centre (ATC). 

Read more


Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Natural Pearls: Marie Antoinette's £27.8 million Precious Pendant

Famous for her ostentatious sense of style, 18th century French Queen Marie Antoinette was back as the centre of attention at Sotheby's in November thanks to the record-breaking sale of her natural pearl and diamond pendant. Here, Beth West FGA DGA EG considers the history behind this fascinating piece. 

Read more


Birthstone Guide: Tanzanite for Those Born in December

Birthstone Guide: Tanzanite for Those Born in December

Looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers the December birthstone tanzanite and how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Journal Digest: Bumble Bee Stone from Indonesia

Journal Digest: Bumble Bee Stone from Indonesia

Guy Lalous ACAM EG delves into an article on Indonesian Bumble Bee Stone (BBS) from The Journal of Gemmology Volume 36, No.3, and presents his edited take on the most essential information, findings and lessons to be learnt. Continue reading here...

Read more


Retail Focus: Beyond the Green

Retail Focus: Beyond the Green

From the Summer 2018 issue of Gems&Jewellery, Gem-A Gemmology Tutor Beth West FGA DGA EG explores Colombian emeralds. 

Read more


Additional Info

Read more...

Whitby Jet: A Discussion of its Simulants

Sarah Steele FGA DGA discusses the many simulants of one of Britain’s most famous native gemstones, Whitby jet.

If imitation is the sincerest form of flattery, then Whitby jet must be a very desirable material indeed. I can think of perhaps 20-30 different materials, both natural and synthetic, which, at one stage or another over the years, have been described as Whitby jet.

We think of a 40-year period during the mid to late nineteenth century as the heyday in Whitby jet manufacture, and from a jewellery output perspective that is unequivocally true. However, the desire for Whitby jet, and the quest to imitate it, has its roots much further back in time. 

Read more: Reconstructed Amber Broken Down

Following the Scottish Gemmological Association’s Conference this year, delegates had the opportunity to visit the 'Celts' exhibition at The National Museum of Scotland. I couldn’t resist the opportunity to join them in having a closer look at the museum’s stunning collection of Bronze Age jet neckpieces whilst we were there.

Historically, many of these early pieces containing black beads with high organic carbon content were described as Whitby jet. Modern analytical techniques have shown, however, that these almost always contain a variety of materials - Whitby jet, certainly - but also oil shales, lignites and cannel coals, often within the one piece of jewellery. 

Inchmarnock Bronze Age necklace showing use of multiple black materials. Photo credit Alison Sheridan. Whitby jet
Inchmarnock Bronze Age necklace showing use of multiple black materials. Photo credit Alison Sheridan

Whitby jet is a material with which the demand for rough will always outstrip supply in periods of high production, and jet collection requires patience as it is reliant on coastal erosion. Are we then, in the Bronze Age some 4,500 years ago, seeing the first example of a Whitby jet simulant? It has to be noted that the prevalence of Whitby jet in the archaeological record during this period suggests that it is arguably one of the oldest economic resources in the British Isles.

Fast forward 2,670 years and the Whitby jet simulant market is a fascinating and booming industry. British society is participating in a national obsession with mourning. With the death of George IV in 1830, the Lord Chamberlain’s office dictates the dress code for the period, stating unequivocally that “the ornament shall be jet”. In 1830 the term ‘jet’ meant only one material: Whitby jet. The death of the Duke of Wellington in 1852 prompted the production of Whitby jet jewellery into overdrive - the 50 recorded workshops in 1850 swelled to 204 following the death of Prince Albert in 1861, as yet another wave of mourning swept the nation. 

Read more: From Elizabeth I to Elizabeth Taylor with John Benjamin FGA DGA

Demand for rough Whitby jet was beginning to outstrip supply and other options were needed. The main attraction of Whitby jet as a gem material was of course its deep black colour and liquid-like lustre, but more importantly its low specific gravity (SG) 1.2-1.3. It was fine to look ‘weighed down’ by the convictions of your expression of mourning, but it was practical if the seven strings of beads you wore to denote that you were the seventh daughter of a deceased father, didn’t weigh more than a few ounces.

Therefore, to be a convincing simulant of Whitby jet, the imitation material would need to be light in weight. Whitby jet is also a poor thermal conductor and so always feels warm, as heat is not quickly transferred away from the surface. Today we often describe jet as feeling ‘plasticky’, however, in the mid nineteenth century plastic was yet to be discovered. The simulant therefore needed to be light in weight, black in colour and a poor conductor of heat. 

Horn and tortoiseshell

In 1712 John O’Bisset discovered horn could with the application of heat, be moulded into various shapes. When cooled the shape was retained - O’Bisset had discovered the first natural thermoplastic material. Sheets of horn were put between hot metal plates in a press and pressure applied. Placing the warmed horn into moulds before applying pressure enabled the production of horn boxes, beakers and other items. With the application of black dye, pressed horn was a good candidate for a simulant of Whitby jet and many jewellery items were produced. 

Horn has a tendency to delaminate due to its layered structure, so loupe examination often reveals these layers, especially on the reverse of brooches. Any damage to the edges also gives a slight transparency to the damaged area, which is not seen in Whitby jet. The colour can often seem uneven and it is not possible to screw a brooch fitting into jet. Therefore a screw, often seen in horn, is always a sign of a simulant. 

Pressed horn jewellery items. Whitby jetThe reverse of a pressed horn brooch showing lamination and screw fittings. Whitby jet
Top: Pressed horn jewellery items. Below: The reverse of a pressed horn brooch showing lamination and screw fittings

It is also worth mentioning that tortoiseshell, like horn, is also a natural thermoplastic. Tortoiseshell, a much admired decorative material, derives not from a land tortoise but from certain species of marine turtle, principally the relatively small hawksbill. Tortoiseshell is unlikely to be mistaken for jet due to the mottled colour, but the SG and ‘plasticky’ feel are similar.

Bog oak

Whitby jet is a fossilised wood, so perhaps a wood product could also make a suitable simulant. Bog oak is not a specific species, rather a term that indicates wood that has been buried in a peat bog for thousands of years. The extremely low oxygen conditions of the bog protect the wood from normal decay. While the underlying peat provides acidic conditions where iron salts and other minerals react with the tannins in the wood, gradually giving it a distinct dark brown to almost black colour. 

Bog oak jewellery. Whitby jet
Bog oak jewellery

Bog oak occurs in many areas of the United Kingdom but jewellery usually originates from Ireland. It was produced from the early 1800s but became popular in the mid nineteenth century, reflecting the demand for Whitby jet, especially after 1852, when techniques to mass-mould and decorate the material (through the application of hydraulic or heated pressure to the dried wood) were invented. 

Although predominantly used for mourning jewellery as a cheap substitute for Whitby jet, bog oak was also worn to support Irish crafts, with pieces often carved or stamped with Gaelic motifs such as harps or shamrocks - symbols not normally found in mourning jewellery. Concentric rings are usually visible on the reverse of items as blanks were lathe-turned prior to carving. Loupe examination always show the ligneous nature of the wood and the lustre achieved is usually textured and dull.

Vulcanite

In 1839 Charles Goodyear discovered the method of mixing sulphur with rubber to form hardened or vulcanised rubber, called Vulcanite. The proportion of sulphur can be increased or decreased in order to vary the required amount of hardening accordingly. Between 25-50% sulphur gives a hard product with the familiar feel of plastic. There are many Victorian vulcanite objects, but the most common form is an imitation of Whitby jet used widely in the production of brooches, bracelets and necklaces. Vulcanite could be produced in almost any colour, although the predominant colours are black (ebonite) and brown. As a result, vulcanite was by far the most widely-produced Whitby jet simulant. Unlike pressed horn a thermoplastic materials which, if heated again can be re-moulded into a different shape. Vulcanite is a thermoset material which, after moulding becomes brittle and cannot be remoulded. 

Vulcanite can be distinguished from jet relatively easily. If the material has been exposed to light over time it loses its black colour and becomes khaki brown. When rubbed, vulcanite smells strongly of sulphur and brooch pins are usually screwed into position rather than glued. Chain links only show one or two splits depending on the link style as the link can be twisted open and then closed. In comparison in Whitby jet links, where every other link in the chain is cut and glued and will always show two or three cuts depending on the style of link. As vulcanite pieces were often moulded from jet originals the same design is seen regularly and, with experience, can be identified easily. (Please note: the ‘streak’ test on vulcanite will reveal a light brown streak similar to that of hard Whitby jet and so should not be relied on).

Examples of vulcanite jewellery. Items with little exposure to light remain black (left). Items that have been exposed to light show the typical khaki colour (right). Whitby jet
Examples of vulcanite jewellery. Items with little exposure to light remain black (left). Items that have been exposed to light show the typical khaki colour (right)


Bois durci

In 1855 Francois Charles Le Page secured a French patent for a method of combining blood albumen from slaughterhouses, with wood powder to form a plastic mouldable material he called bois durci. The wood dust (either ebony or rose wood), was mixed with blood, dried and then ground to a fine powder. The powder was placed in a steel mould and steam heated to 150-250°C in a powerful hydraulic press. After half an hour the mould was plunged into cold water. The resulting wood product was an extremely dense, highly polished and resistant thermoset material. 

Prince Albert plaque made from bois durci. Whitby jet
Prince Albert plaque made from bois durci

Le Page is reported to have used the marketing strapline “Anything Whitby Jet could do, bois durci could do cheaper and in brown”. The most common items available in bois durci today are circular plaques showing royalty or statesmen of the time. They are generally brown and often have bois durci stamped on the reverse.

French jet and Vauxhall glass

As far as Whitby jet imitations go French jet, along with vulcanite one of the most common. Glass items were also produced in large quantities during the Whitby jet heyday, primarily faceted black glass beads referred to as French jet. 

Its higher SG, vitreous lustre and glass moulding marks mean it is unlikely to confuse French jet with Whitby jet. However, because many of the designs were so innocuous, finding a nineteenth century piece of French jet and identifying it from a piece of black glass, used all the way through to the 1940s, can be difficult for collectors of the material. 

Vauxhall glass is often referred to as the English version of French jet, however all French jet was not of course produced in France! This thin highly reflective mirror glass was produced by a silvering process. The silvering is often seen on the reverse - either intact or in residual traces. 

The back of a Vauxhall glass earring: silvering visible on edges. Whitby jet
The back of a Vauxhall glass earring: silvering visible on edges

Spanish jet

Although all the above impacted the Whitby jet industry, it was a natural jet which was finally responsible for the industry decline. By 1870 the Whitby jet industry reached its peak, before catastrophically collapsing. There were undoubtedly a number of reasons. Some blamed the terrific demand, which had outstripped supply and lead to a fall in standards of workmanship, as many workers hadn’t had the basic training. The large number of simulants also cannot have helped, but the final death knell was heralded by the arrival from the continent of Spanish jet. It is hard to estimate how much of this material was imported from Asturias, but it is first documented in 1874 and many tonnes seem to have been available. 

The Spanish jet trade had flourished between seventh and sixteenth centuries, and whilst the Spanish supply undoubtedly had some very good quality rough material, it seems that Whitby imported a rather poor quality jet, often containing pyrite, making it unstable. Finished pieces degraded quickly, cracked and crumbled. As a result, consumer confidence in an already struggling product sector collapsed.

Three faceted bead necklaces, cracked and crazed beads, likely Spanish jet (left), Whitby jet, showing high lustre and sharp facet edges (centre), French jet with chips and abraded facet edges (right). Whitby jet
Three faceted bead necklaces, cracked and crazed beads, likely Spanish jet (left), Whitby jet, showing high lustre and sharp facet edges (centre), French jet with chips and abraded facet edges (right)


Decline of the industry

In 1889 the Whitby Gazette reported “It would have been better for the Whitby jet Industry, and better for art development, if the Spanish jet trade had never been known in Whitby”. Despite desperate measures to support the Whitby jet industry, such as a quality mark scheme, the industry didn’t recover. The mourning trend was well and truly over. 

In 1915 The Lady described the Whitby jet trade as “A somewhat funereal fetish of fickle fashion”. Poor recognition for the greatest lapidary trend our nation, and perhaps the world has ever seen. 

The beginning of the twentieth century may have heralded the end of the Whitby jet mourning jewellery trend, but it didn’t signal the end of the road for the use of plastics in jewellery. In 1899 we saw the introduction of casein formaldehye; milk curds hardened with formaldehyde giving us such famous trade names as Galilith, and of course in 1907 phenol formaldehye, with wood flour or other filler as powder gives us the trade name Bakerlite. Galilith and Bakerlite were never used to imitate Whitby jet jewellery - by this time (and forgive the pun) you wouldn’t have been seen dead in this outdated material.

It seemed like the end of the road for Whitby jet. The last apprenticed jet worker Joe Lyth died in 1958, and with him died the secrets of the Victorian era. However, the last 30 years or so we have seen a revival in fortunes within the Whitby jet trade. Today there are 11 manufacturers in Whitby town. As mentioned previously, demand for rough Whitby jet is high and patience is required for collection of beach material. This has allowed poor quality materials, primarily Siberian cannel coals and Georgian jet (both often referred to as Gagate) with its poor stability and high porosity to enter the supply chain. 

Georgian jet is becoming increasingly common as finished contemporary style jewellery made by Baltic amber manufacturers, and within the last 12 months as antique style beads from an undisclosed source. Attempts were even made to sell rough to unsuspecting workshops in Whitby. Experienced lapidaries however quickly identified the new foreign imposter. In Whitby we have no issue with Georgian manufactures producing items from their indigenous jet, but lack of disclosure of origin leads to the material being retailed as Whitby jet somewhere along the pipeline.

Nomenclature and appellation of origin is, as always, crucial to price. A good Whitby jet string of Victorian beads is worth £300 upwards, the Georgian imitation probably nearer £20, so caveat emptor!

As a lapidary in Whitby, I know that the Whitby jet trade will, as always fight back against the latest simulants. A true jet to rival the beauty or stability of Whitby jet has yet to be discovered, but it does make me proud to think that for the last 4,500 years Whitby jet has been held with such reverence that many have tried to emulate it. With the desire of the Victorians to find the perfect simulant, Whitby jet was in part perhaps responsible for the birth of the modern plastics industry, and therefore the modern world as we know it. ■

This article originally appeared in Gems&Jewellery May/June 2016 / Volume 25 / No. 3 pp. 16-20

Interested in finding out more about gemmology? Sign-up to one of Gem-A's courses or workshops.

If you would like to subscribe to Gems&Jewellery and The Journal of Gemmology please visit Membership.

Cover image fine Whitby jet cameos including King Oswy and his bride (centre) and Bejamin Disraeli (right). Photo Credits Sarah Steele, except where otherwise stated. 


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The Tale of the Mouawad-Tereschenko Blue Diamond

Jack Ogden FGA looks into the story of the world's second largest blue diamond, the Mouawad Blue Diamond, previously known as the Tereschenko Blue Diamond. 

In the summer of 1984 David Warren, now Senior International Jewellery Director at Christie’s, received a phone call from the auction house’s bank manager with a question: “Do Christie’s sell blue diamonds? Our client has one the size of a pigeon’s egg.”

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The huge gem turned out to be the Tereschenko diamond, one of the least well known large blue diamonds, and at 42.92 ct, just a shade smaller than the 45.52 ct Hope. It sold at Christie’s in Geneva in November 1984 for a then-record price of $4.6 million to Robert Mouawad and is now called the Mouawad Blue. Unlike the Hope and many of the other famous diamonds, it has lacked a romantic history.

There has been no curse or celebrated Mughal emperor to add notoriety or spice. The Christie’s catalogue, and Lord Balfour in his standard work on the world’s great diamonds, simply notes that the first known appearance of the stone was in 1913 when the Ukrainian Mikhail Tereschenko left it with Cartier in Paris. 

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In 1915 he instructed them to mount it in a necklace, which was returned to him in Russia before being spirited out of the country again in 1916, on the eve of the Russian Revolution. Then according to Christie’s and Balfour, it passed into anonymous private ownership until it came up at auction in 1984. 

Perhaps we can now add some spice, even a curse, to this story, by introducing a French dancer born in the final decade or so of the nineteenth century. She entered the entertainment world under the stage name of Mademoiselle Primrose and by 1911 was performing in Le Théâtre des Capucines in Paris. She was renowned for her attractiveness and, in a rather surreal article on the components of female beauty in Paris that appeared in various American newspapers in late 1911 and early 1912, she was noted as one of the most beautiful of reigning stage beauties in Paris with particular praise for her “most charming chin”.

Suzanne Marie Blanche Thuillier ca 1920. Tereschenko diamond
Suzanne Marie Blanche Thuillier ca 1920

If Mikhail Tereschenko left the 42.92 ct blue diamond with Cartier in Paris in 1913 he may have encountered Mlle Primrose in that city. This is not such a wild suggestion because in 1924 we hear of a former Parisian dancer named Mlle Primrose, real name Suzanne Marie Blanche Thuillier, who had resided for a time in St. Petersburg, Russia, and who moved in Court circles there. She had left Russia for France just before the Revolution and was the owner of what was described as a 43 ct blue diamond, called by some the ‘Russian Imperial Blue’, and by others (rather bizarrely) the ‘Blue Diamond of Ceylon’.

The newspapers at the time gave myriad origins for the stone, neither verified nor mutually exclusive. It came from the eye of an idol in India; reached Russia in the time of Peter the Great; had been set in the Russian Crown Jewels; had been secretly purchased in London “under romantic circumstances” and so on. 

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One newspaper even hedged its religious bets and said the gem had “ornamented the finger of Buddha in a Hindu Temple". Particularly intriguing is a report in a British newspaper that "In April 1912, there were rumours in Hatton Garden that a diamond merchant was walking about with a quarter of a million in his wallet. In fact he had received from his Dutch agents a stone [a large blue diamond] which had been sent from America with instructions to let it fetch what it would."

This merchant supposedly pieced together the history of gem, found out that it had once belonged to the Russian Imperial family and put out feelers, which reached the then-Czar who sent an emissary to obtain it. Perhaps more about this supposed transaction will come to light, but in the meantime we can observe that a presence on the market in London in 1912 would tie in nicely with Tereschenko depositing a large blue diamond with Cartier in Paris in 1913.

After Mlle Thuillier and her diamond reappeared in France, some newspapers reported that she had been given it by Czar Nicholas as a token of his regard for her; others that it was given to her by "a member of the Imperial Court of Nicholas". The latter view was supported by those in the know who vehemently denied, or expressed indignation, at the suggestion that the late Czar gave Thuillier the diamond. Indeed, according to Le Parisien newspaper in June 1924, when directly asked where it came from Thuillier explained “evasively” that strictly speaking she was not admitted to the imperial court, but “frequented assiduously with the gentlemen of the court who occupied the highest positions”. She never claimed that the diamond was presented to her by the Czar. So, if a gentleman other than the Czar gave her the gem, Mikhail Tereschenko is perhaps a potential contender. 

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Was a gift of the blue diamond the ticket to a new life outside Russia on the eve of the Revolution? She reportedly arrived in Nice in the South of France in 1916 and pawned it there that same year. The diamond had travelled in a secret pocket of her sealskin coat. 

Following her arrival in the South of France, Mlle Thuillier’s beauty and attire "made her a spectacle among the many lovely women". However, she gambled excessively and this "most notoriously extravagant woman in Europe" inevitably got into debt and had to pawn the blue diamond more than once. In June 1924 the diamond was in pawn for 200,000 francs with creditors circling, but there was the expectation that it would be redeemed and available for purchase. Apparently a Parisian dealer had already offered £125,000 and an American woman £200,000. 

The Tereschenko or Mouawad Blue Diamond
The Tereschenko or Mouawad Blue Diamond

What then occurred is unclear. There are reports that a Joseph Paillaud of Cap d’Ail, near Nice, had put up collateral of 1,350,000 francs and would take ownership of the diamond if not repaid in full by 9 December 1924. Mlle Thuillier made a plea to the Court and in March 1925 the Civil Court in Nice removed it from Paillaud’s possession. Apparently Paillaud’s actions equated with acting as a pawnbroker, an activity for which he was not licensed. A police search of his house - named, ironically, Chalet Russe (Russian Chalet) - revealed numerous pieces of jewellery lacking the required hallmarks plus records of transactions that were not properly registered.

Mlle Thuillier might well have predicted Paillaud’s bad luck. A newspaper report in 1929 recounted that she had believed the diamond to be cursed. This may be typical press sensationalism, but some accounts say she was something of a mystic with an interest in the occult and in 1924 was even considering taking the gem back to India so it might be replaced on the statue of Buddha from which it had been robbed. It clearly never made it back to the statue and the last we hear of the large blue diamond is in March 1925, in the custody of the clerk of the civil court in Nice.

The last we hear of the celebrated Mlle Primrose - with her charming chin - is in jail in Nice in April 1929, after several years of dire poverty. Her desperate situation had driven her to forgery. What happened to the large blue diamond from 1925, until it resurfaced at Christie’s Geneva in 1984 is so far unknown, but a French newspaper in 1924 had already commented that the diamond had "undoubtedly not yet finished the cycle of events of its adventurous life". 

Note: The above was compiled from contemporary press accounts from Europe and America. Their lack of accuracy is demonstrated by their confusions and contradictions, so for now this is a tale of the Mouawad-Tereschenko diamond, not necessarily the tale of the Mouawad-Tereschenko diamond 

This article originally appeared in Gems&Jewellery March/April 2016 / Volume 25 / No. 2 pp. 32-33

Interested in finding out more about gemmology? Sign-up to one of Gem-A's courses or workshops.

If you would like to subscribe to Gems&Jewellery and The Journal of Gemmology please visit Membership.

Cover image an exact CZ replica of the Mouawad blue.


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