The History of Diamonds in Engagement Rings

Jack Ogden FGA takes a look at the history of diamonds being used in engagement rings. You might be a little surprised at how far the custom dates back...

Here is a question for you. Read this sentence about engagement rings: “As for the engagement ring, modern fashion prescribes a diamond solitaire, which may range in price from two hundred and fifty to two thousand dollars.” When do you estimate that was written? Before or after World War II? 

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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 of the United Kingdom.

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 Crown Jewels: 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 Crown Jewels: 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.

The Crown Jewels: 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 Crown Jewels: 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 Crown Jewels: 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).


The Fascinating History of Antique Turquoise Jewellery

The Fascinating History of Antique Turquoise Jewellery

In his third Gemstone Conversations column for Gems&Jewellery, Jewellery Historian and Valuer John Benjamin FGA DGA FIRV explores the fascinating history of turquoise and its use in jewellery design from the Shahs of Persia to the Art Deco design movement.

Read more


Birthstone Guide: Garnet For Those Born In January

Birthstone Guide: Garnet For Those Born In January

If you're lucky enough to be born in January, vibrant garnet is your birthstone. A rainbow jewel of the gem world, garnet displays the greatest variety of colour of any mineral and is very often untreated, making it a rarity in the gem world. 

Read more


Getting Started with Quartz Inclusions

Getting Started with Quartz Inclusions

Do you know your calcite inclusions from your dumortierite, epidote, fluorite and rutile? Here, Charles Bexfield FGA DGA EG explores some incredible quartz inclusions and explains what to look for when shopping for quartz specimens.

Read more


Understanding Iridescence: Opals, Pearls, Moonstones and Fractured Stones

Understanding Iridescence: Opals, Pearls, Moonstones and Fractured Stones

Iridescence has to be one of the most mesmerising and magical optical effects seen in gemstones. But have you ever wondered how it occurs? Gem-A's Collection Curator Barbara Kolator FGA DGA shines a light on this fascinating optical effect and tells us about the gems that are most likely to display it.

Read more


Hidden Treasures: Highlights of Gem-A's Gemstones and Minerals Collection

Hidden Treasures: Highlights of Gem-A's Gemstones and Minerals Collection

Gem-A Gemmology Tutor Pat Daly FGA DGA offers us a glimpse at some of the more unusual items in Gem-A's Gemstones and Minerals Collection.

Read more


Tanzanite: The Contemporary December Birthstone

Tanzanite: The Contemporary December Birthstone

Are you looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers tanzanite – one of three birthstones for December – and shares how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Birthstone Guide: Turquoise For Those Born In December

Birthstone Guide: Turquoise For Those Born In December

Beautiful blue turquoise is one of three birthstones for the month of December (in addition to zircon and tanzanite). It is enriched with real cultural significance that can be traced back thousands of years. Here, we explore the blue shades of turquoise and explain what makes this gemstone so special...

Read more


Understanding the Cat's Eye Effect in Gemstones

Understanding the Cat's Eye Effect in Gemstones

Chatoyancy is the gemmological name given to the curious optical effect in which a band of light is reflected in cabochon-cut gemstones, creating an appearance similar to light bouncing off a cat's eye. Gem-A's Collection Curator, Barbara Kolator FGA DGA explains chatoyancy and highlights some of the many gems in which it can occur.

Read more


Jade and its Importance in China

Jade and its Importance in China

Jade has long been revered by gem lovers internationally, but nowhere more so than in China. But what is it that makes this gemstone so special? Gem-A's Assistant Gemmology Tutor Dr Juliette Hibou FGA gives us an overview of jade, how to identify it and its significance in Chinese culture.

Read more


Highlights of Gem-A Conference 2019

Highlights of Gem-A Conference 2019

The Gem-A Conference is always the highlight of our gemmological calendar! If you didn’t manage to make it, we’ve put together a few of the highlights from this year’s event to fill you in on what you missed, and whet your appetite for Gem-A Conference 2020!

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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.”

Mouawad-Tereschenko Blue Diamond

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. 

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

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. 

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. 

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.


The Fascinating History of Antique Turquoise Jewellery

The Fascinating History of Antique Turquoise Jewellery

In his third Gemstone Conversations column for Gems&Jewellery, Jewellery Historian and Valuer John Benjamin FGA DGA FIRV explores the fascinating history of turquoise and its use in jewellery design from the Shahs of Persia to the Art Deco design movement.

Read more


Birthstone Guide: Garnet For Those Born In January

Birthstone Guide: Garnet For Those Born In January

If you're lucky enough to be born in January, vibrant garnet is your birthstone. A rainbow jewel of the gem world, garnet displays the greatest variety of colour of any mineral and is very often untreated, making it a rarity in the gem world. 

Read more


Getting Started with Quartz Inclusions

Getting Started with Quartz Inclusions

Do you know your calcite inclusions from your dumortierite, epidote, fluorite and rutile? Here, Charles Bexfield FGA DGA EG explores some incredible quartz inclusions and explains what to look for when shopping for quartz specimens.

Read more


Understanding Iridescence: Opals, Pearls, Moonstones and Fractured Stones

Understanding Iridescence: Opals, Pearls, Moonstones and Fractured Stones

Iridescence has to be one of the most mesmerising and magical optical effects seen in gemstones. But have you ever wondered how it occurs? Gem-A's Collection Curator Barbara Kolator FGA DGA shines a light on this fascinating optical effect and tells us about the gems that are most likely to display it.

Read more


Hidden Treasures: Highlights of Gem-A's Gemstones and Minerals Collection

Hidden Treasures: Highlights of Gem-A's Gemstones and Minerals Collection

Gem-A Gemmology Tutor Pat Daly FGA DGA offers us a glimpse at some of the more unusual items in Gem-A's Gemstones and Minerals Collection.

Read more


Tanzanite: The Contemporary December Birthstone

Tanzanite: The Contemporary December Birthstone

Are you looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers tanzanite – one of three birthstones for December – and shares how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Birthstone Guide: Turquoise For Those Born In December

Birthstone Guide: Turquoise For Those Born In December

Beautiful blue turquoise is one of three birthstones for the month of December (in addition to zircon and tanzanite). It is enriched with real cultural significance that can be traced back thousands of years. Here, we explore the blue shades of turquoise and explain what makes this gemstone so special...

Read more


Understanding the Cat's Eye Effect in Gemstones

Understanding the Cat's Eye Effect in Gemstones

Chatoyancy is the gemmological name given to the curious optical effect in which a band of light is reflected in cabochon-cut gemstones, creating an appearance similar to light bouncing off a cat's eye. Gem-A's Collection Curator, Barbara Kolator FGA DGA explains chatoyancy and highlights some of the many gems in which it can occur.

Read more


Jade and its Importance in China

Jade and its Importance in China

Jade has long been revered by gem lovers internationally, but nowhere more so than in China. But what is it that makes this gemstone so special? Gem-A's Assistant Gemmology Tutor Dr Juliette Hibou FGA gives us an overview of jade, how to identify it and its significance in Chinese culture.

Read more


Highlights of Gem-A Conference 2019

Highlights of Gem-A Conference 2019

The Gem-A Conference is always the highlight of our gemmological calendar! If you didn’t manage to make it, we’ve put together a few of the highlights from this year’s event to fill you in on what you missed, and whet your appetite for Gem-A Conference 2020!

Read more


Additional Info

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The Most Underappreciated Gemstone? Why We Love Rock Crystal

Everyone knows that lucky April-born souls have been blessed with one of the most prestigious birthstones: diamond. However, there is an alternative birthstone for the month and it's a 'hidden gem'... so to speak! Gem-A Member, Julia Griffith FGA DGA EG explains why rock crystal is worth your time and attention. 

Rock crystal is the purest variety of quartz and is transparent and completely colourless. Its name derives from the Greek term krustallos meaning 'ice' and it is the sister gemstone to colourful varieties of quartz, such as amethyst and citrine. 

What makes rock crystal special?

From across the spectrum of gemstones, only rock crystal offers such a wide variety of attractive inclusions. For this reason, rock crystal has the potential to be one of the most characterful and artistic gemstones for collectors and jewellery lovers alike. 

Quartz crystal cluster Tucson. Photo by Julia Griffith. April birthstone.
Quartz crystal cluster photographed at the Tucson gem shows. Image courtesy of Julia Griffith.

Many may think of 'inclusions' as flaws, however, when viewing the array of possible features that can be available within this gemstone one may change this opinion. There is rutilated quartz, tourmalinated quartz, fluorite in quartz, hematite in quartz, gilalite in quartz, pyrite in quartz… the list goes on! These different mineral inclusions add further variety to the rock crystal family whilst offering dozens of different looks.

Read more: Navigating Enhanced Versus Natural Lapidary Materials 

Rutile in quartz. Image courtesy of Julia Griffith. April birthstoneRutile in quartz. Image courtesy of Julia Griffith.

Considering its place in the quartz family of gemstones, rock crystal has a hardness of 7 on the Mohs Scale. It is reasonably durable and stable, which makes it suitable for all kinds of jewellery pieces. It can be fashioned as carvings, cabochons or faceted gems.

Read more: The Historic Significance and Mythology of Amethyst 

An additional bonus with quartz is that it is readily available in larger sizes and at wallet-friendly prices. If you are searching for a statement pendant, beautifully-included rock crystal could be a fantastic option. 

Fluorite in Quartz. Image courtesy of Julia Griffith. April birthstone.Fluorite in quartz. Image courtesy of Julia Griffith.

The Uses of Rock Crystal

Transparent rock crystal has been used as an imitation of diamond for centuries, due to the fact they are both colourless. Rock crystal will not be as 'firey' as diamond as it does not disperse light to the same degree, however, a well-cut rock crystal can be very brilliant with excellent return of white light.

Faceted rock crystals are still used as diamond imitations today, particularly as 'accent stones' in jewellery. Designers may choose to surround a coloured stone with melee-sized rock crystals rather than diamonds, offering affordable price-points to the consumer whilst giving a similar look.

Quartz Crystal Formation

Quartz is a silica (SiO2) and is the most abundant mineral on Earth and therefore it is mined in many localities throughout the world. Quartz grows as long prismatic crystals with pyramidal points that can occur as single crystals, clusters and geodes - all of which can be very attractive and are commonly used as display pieces or set within jewellery. The largest single crystal recorded was from Itapore, Brazil and measured over 20 feet in length and weighed over 44 tonnes.

The industrial uses for rock crystal quartz outweigh its use in jewellery. It is used within the manufacture of glass, sand, ceramics, brick and abrasives (to name a few) and it is considered one of the world’s most useful natural materials.

Hematite in quartz. Image courtesy of Julia Griffith. April birthstone.
Hematite in quartz. Image courtesy of Julia Griffith.

Understanding Synthetic Quartz

Since its successful synthesis in the 1950s, synthetic lab-grown quartz is used extensively for the majority of industrial processes and may also be found within the gem trade as fashioned stones. 

Notably, quartz is used in the mechanism of quartz watches (hence the name) and anyone who sells watches will know that quartz movements keep exceptionally accurate time losing only seconds over the life-time of the battery. This is thanks to quartz’s ability to release regular electronic impulses at precise frequencies.

This rare property, known as piezoelectricity, is utilised within our GPS equipment, telephones and radios as well as in the mechanism, which triggers the airbags in our cars.

Quartz crystals in Tucson. Image courtesy of Julia Griffith. April birthstone.
Quartz crystals in Tucson. Image courtesy of Julia Griffith.

It is this property, which is thought to be exploited during crystal healing as the energy held within rock crystal is thought to amplify and channel universal energy. Hopefully, we have managed to change your mind about rock crystal! Why not celebrate April births and special occasions with this underappreciated gemstone instead of the diamond? You may just fall in love with something new. ■

Get started on your gemstone journey with gemmology courses and qualifications from Gem-A. Find out about the Gemmology Foundation and Gemmology Diploma here

Do you have a passion for diamonds? Discover the Gem-A Diamond Diploma and Short Courses hereand Short Courses here

Cover image Tourmaline in quartz. Image courtesy of Julia Griffith.

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Exploring a Spectrum of Diamonds with the Aurora Pyramid of Hope

Curator Alan Bronstein reveals how the world-renowned Aurora Pyramid of Hope evolved and shares the story behind his lifelong passion for coloured diamonds. 

Diamonds shown are between 0.5-1.5 ct. Copyright Aurora Gems Inc. Image courtesy of Robert Weldon.
Diamonds shown are between 0.5-1.5 ct. Copyright Aurora Gems Inc. Image courtesy of Robert Weldon.

It is difficult to trace all the challenges, twists and turns, triumphs and failures, which characterise the journey of a dream from fantasy to reality. For me, it all began with one experience, one stone, and one revelation. In 1977, as a college graduate who could not find a job, it was suggested by my mother Jeanette, the book-keeper at the New York Diamond Dealers Club, that I become a diamond broker. 

Such a job only required you try to sell loose colourless diamonds from one dealer to another. Such a job did not require any skills other than banging on doors (you could still do that in 1977) and getting offers on the diamonds you were soliciting. I found it to be one of the least fulfilling ways I could spend my time, as diamonds were already becoming commoditised by the price lists all diamond dealers carried. As a result, the illusion of what might be a visually beautiful stone disintegrated when it was deemed not to fit within the defined parameters of the emerging grading system, which qualified the stone on paper as a commodity. 

As fate often intervenes at the moment it is most necessary, just as I was about to make my break for the unknown, I saw something I had never seen in my years as a diamond broker; a yellow diamond that shined like the sun, hypnotising me and opening my mind to something new and exciting. Although it was part of the natural diamond world, it was a well-kept secret. Not because they had no beauty but because diamond dealers did not know how to make money with them, and thought they were the poor cousins to the 98% highly-promoted and coveted colourless diamonds. There were no discussions about them, they were never advertised and remained an underground trade that was only mentioned among the few aficionados in the diamond industry who collected them as curiosities, simply because they could not sell them. 

Into this small group of connoisseurs, I was embraced as a broker and as a peer because of my intuition for recognising the idiosyncrasies within the colours of the diamonds. This small group of mentors allowed me into their private world, and I learned what to keep my eyes open for from their experience and knowledge. This is the ultimate and true way to learn, from the wisdom of experts that have come before you. What a gift to be allowed to study among this exclusive club of dealmakers. 

Starting with Yellow Diamonds

The first thing I learned was not all yellow diamonds have the same colour characteristics. I saw all different colour reflections in almost every stone I looked at carefully. At this time, in 1980, the grading system so highly-regarded in colourless diamonds was generalised in coloured diamonds, to say the least. All yellowish diamonds were called yellow. All pinkish diamonds called pink. Yet when you had an opportunity to make comparisons, you could often see major differences in saturation and colour modifiers that were not identified by the labs. 

Instinctively, one could tell that the science of natural colour diamonds was in its infancy and that to determine a greater hierarchy of colours, perceived as more desirable, would be an advantage to finding, selecting, buying and selling the prettiest stones. It was the fork in the road I was travelling. 

The Aurora Pyramid of Hope collection - polished diamonds. Image courtesy of The Trustees of NHM, London.
The Aurora Pyramid of Hope collection - polished diamonds. Image courtesy of The Trustees of NHM, London.

I set out to find small sample stones that would be my standard for analysing differences that were hard to notice without comparison. These few small sample stones became the foundation for my business and for the concept that would become the Aurora Pyramid of Hope. 

Soon my interest and passion turned into an obsession. Every day I would enthusiastically go hunting for unusual diamonds as the colour matrix began to fill in. Often I would see something new, something different, quite often with dealers who did not know what to do with their curiosity. 

Soon I realised even though many stones had similar colour characteristics and intrinsic colours, when scrutinised subtle differences would become clearer leaning toward a spectral modifier. Even the shape and cut, angles and facet arrangements of the stone would change the appearance of the face up colour. 

Sourcing Coloured Diamonds 

This was a turning point, as I decided without the means to do so, that I would try to organise a collection with as many different colours as I could find, afford and obtain. The colour of the stones, many of which one would find extraordinary and many that were commonly seen, would be the primary driving force for gathering. Other factors like size, natural inclusions, and natural phenomena like fluorescence were secondary to trying to find stones that fit the universal matrix of colour in nature and specifically diamonds. 

For the last 37 years, beginning with the first sample stone to the present, I have collected 296 diamonds that now compose the Aurora Pyramid of Hope. The collection has gone through a metamorphosis in its composition and its meaning. It has served a great purpose for science, through studies of its colours at museums and laboratories around the world, and revealed many secrets that have advanced our understanding of these rare gemstones. 

Waterfall: Polished diamonds from the Aurora Pyramid of Hope collection. Copyright The Trustees of NHM, London. Image courtesy of Robert Weldon.
Waterfall: Polished diamonds from the Aurora Pyramid of Hope collection. Copyright The Trustees of NHM, London. Image courtesy of Robert Weldon.

As the colour matrix began to fill in, it took on a new meaning for me. At some moment my consciousness gave way to the concept that the pyramid was not just a science project but also a work of art in a new medium. A painting using only unmounted loose diamonds had never been seen before. 

Introducing the Aurora Pyramid of Hope 

I saw humanity in the collection as it grew. All the colours, shapes and inclusions were the perfect metaphor for all the races, colours, religions, faces of people and the infinite personalities that make us all individuals. I am also of the belief that we are related to diamonds, because we are made from the same essence created by the universe – carbon – the key element in all living things. Although natural diamonds seem inanimate, they reveal life through their brilliance. 

The pyramid shape itself has many spiritual and historical meanings that add to the symbolism I have tried to create. As does the name Aurora, the Roman goddess of the sunrise, and the colourful lights that appear at the northern and southern tips of the earth. 

When the collection was about to go on display at The American Museum of Natural History (AMNH) in New York, all the stones were in parcel paper and it was at this moment that I had to figure out how to present them. As I experimented with different forms, by laying out stones, it soon evolved naturally into the pyramid shape seen today. It unconsciously pulled me in that direction and I was pleased at its display and play of colours. 

I have many favourite stones in the collection; some for their stories and some for their extraordinary colours. One such amazing story is when a South American miner showed me a small rough diamond that was opaque and coated black. He had cut one flat surface into the stone so when you peered through this window it appeared green in colour. Many stones like this were colourless inside when you removed the skin coating the stone, which was caused by natural radiation in the ground. Other stones with this outer skin were often black or ground into diamond powder, because they were not considered gem material.

Green diamond: the original rough on the left and the finished stone emerald cut on the right. Copyright Aurora Gems Inc. Image courtesy of Robert Weldon.
Green diamond: the original rough on the left and the finished stone emerald cut on the right. Copyright Aurora Gems Inc. Image courtesy of Robert Weldon.

This particular stone was re-examined in the lab during the multiple phases of cutting over one year, to make sure it was the same specimen and that it had not been treated from the previous observation. At the end of the process, to my shock and that of the lab, it emerged as the most beautiful natural green diamond I have seen to this day.

The collection is, however, dynamic, and I have continued to collect and look for missing pieces to the puzzle. A further 36 stones were added in 2005 when the collection went on exhibit at the Natural History Museum (NHM) in London, joining the original 260 documented in 1998. I also replaced 20 stones that I felt would improve the variety and aesthetics of the original suite, thus the pyramid is greatly improved from its original museum exposure in 1989 at AMNH in New York where it spent 16 years. 

L-R Dr Jeffrey Post, Harry Rodman and Alan Bronstein in front of the Aurora Butterfly of Peace collection at the Smithsonian. Photo courtesy of Alan Bronstein.
L-R Dr Jeffrey Post, Harry Rodman and Alan Bronstein in front of the Aurora Butterfly of Peace collection at the Smithsonian. Photo courtesy of Alan Bronstein.

The Pyramid of Hope’s sister is the Aurora Butterfly of Peace; a collection evolved from the desire to make a pure artwork painting with natural colour diamonds. It was a 12 year process of building and arranging its mythic shape. Although the concept behind the pyramid began as science and became art, the butterfly began as an artwork and was also a bounty for science. It is proof that nature is science and art, and nature is the greatest artist of all. 

Along with its sister, the Aurora Pyramid of Hope is meant to be a universal non-secular artwork and symbol to point humanity to our common purpose for living; hope, peace and love. It serves as a legacy for all mankind. Alan Bronstein is the curator of the Aurora Pyramid of Hope with the financial assistance of his late step-father and business partner Harry Rodman. ■ 

Gem-A members can log in to read the full article Gems&Jewellery Spring 2017 / Volume 26 / No. 1

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 From the Aurora Pyramid of Hope collection - rough and polished diamonds. Image courtesy of The Trustees of the NHM, London. 

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A Man of the Ocean: Diving for Organics with Eric Fritz

In a recent trip to the London headquarters, Eric Fritz, FDGA DGA manager of North America for Gem-A stopped by for an industry insider Q&A, educating us on theoretical and practical guidance of organic materials. Sarah Salmon speaks to the man of organic passion exploring the nature of these beautiful materials.

With a passion for pearls, a deep love for shells since the age of four and an extensive knowledge of coral, minerals and gemstones, Eric Fritz reveals his top tips when it comes to his specialty: organic gem materials.

Q. When identifying pearl, what are Gemmologists looking out for when grading their quality?

For value, you will be looking at whether it is a salt-water or freshwater pearl, whether it is natural - formed without any human involvement - or whether the pearl has been cultured. The most valuable in terms of quality across the board would be natural saltwater pearls. This would then be followed by natural freshwater pearls, saltwater cultured pearls to freshwater cultured pearls.

Roundness is also preferable when grading a pearl where the more perfectly round and larger it is without blemishes, the more precious it is considered. The bigger the pearl, provided it still has a good ‘roundness’ and lustre finish to it with minimal spots and blemishes to it, the more desirable and valuable it becomes.

Q. What causes the blemishes and imperfections to form on a pearl?

The blemishes are caused by the formation of the organic material itself. Formed by living organisms which, just like us are made up of a range of different imperfections, gives each pearl its unique, flawed composition. The living environment of the shellfish is also a key factor where surrounding waters may contain disease or the shell mechanism itself may malfunction; all of which directly affects the pearl quality.

Q. Where in the world are the most desirable pearls located?

Probably the most desirable and rarest natural pearl will always be the mellow mellow pearl. This is a yellow - golden range commonly found in Myanmar, Burma and Vietnam. The mellow mellow pearl is often hailed as the holy grail of all pearls due to being that of the most value.

The price of a pearl can vary widely in correlation to its size, ranging from $3000 to $65-70,000 at many Gem trade shows, even when such pearls contain blemishes and are therefore still considered imperfect

Q. We often hear about Mikimoto pearls, is this a particular brand or is it a type of organic pearl?

Mikimoto was the first person to commercially produce cultured pearls in Japan in the late 1800’s. Prior to this, cultured pearls had only been produced on an experimental basis but Mikimoto found a technique that he could use to sustainably produce small cultured pearls – typically 7mm - in small saltwater shells.

Its predecessors, being Gem-A, launched the first global Gem lab in London in order to differentiate cultured Mikimoto and natural pearls. The value of each was quite starkly different which meant that many London jewellers became concerned at the introduction of cultured pearls against the trade of more expensive natural pearls. Mikimoto, dating back over 100 years was, and probably still is, the top quality Japanese Akoya pearl on the market.

Q. Being similar in name, what is the key difference between a conch shell and a conch pearl?

Great question! The Conch shell, Lobatus Gigas being its scientific species, occurs only in the Caribbean off the coast of North America, from Florida down through to the West Indies. It is a big shell that was originally gathered by the native people for food due to its very large edible muscle. It is said that 1 in a hundred conch shells could produce a pearl. Conch pearls come in a range of colours from whites to pinks to browns and yellows but it is the pink variety that remains to be the most valuable. We often believe that the very inside of the Conch shell is pink in colour which is why the pink pearl remains the rarest.

However it is also the inside of the conch shell that produces all of the varying colours of conch pearls. Imitations are created when people take the conch shell and try and cut around a bead, passing it off as a genuine pearl. However, these imitations always have concentric bands where, if you look at the side of the bead, you will see what looks like tree ring growth around the edges. This is a kay indication that this is not a real pearl, but an imitation that has been cut out of a shell.

Q. With a huge variety on the market, how do you identify and compare different seashells from one another?

Seashells come in such a wide variety of genus, ranging from freshwater to seawater environments. Dating back to the Victorian times, seashells were and still are highly collectable objects of nature. Linnaeus, founder of the Linnaeus society extensively named over half of the shells we have identified so far. Seashells are very easy to tell the different species apart as they visually look very different from one another.

Today however to differentiate shells via its species level, identification can require DNA analysis to indicate the differences from one shell to the next. They may look very similar but there is stark variation between the different species.

Q. If you’re looking to purchase a high quality shell, what attribute should one be looking for?

People are attracted to different shapes and colour forms with some buying what we call ‘valves’ where two halves of a shell are held together by a muscle, whilst others favour gastropods where the shell is one piece. Some people like to collect a whole family of shells, preferring only to select pieces within the same genus of shells, leading to a lot of variability. Shell prices for collectors range from £2-£3 up to £100,000 for those that are highly desirable.

Q. What are the key differences between 'hard' and 'soft' coral?

A lot of the time when you look at soft corals in its natural habitat under water, they can often look like plants or sea fans which move with the ocean current. They can range in appearance from big broad fans to tall upright branches but most tend to move. Hard coral contains more calcium carbonate than soft and are often what we refer to as coral reef. An expansive garden of skeletons makes up the coral bed where tiny living organisms live within the pores of these hard corals.

Q. Where is Coral found in abundance across the world?

Coral is most commonly found within temperate waters, including the Caribbean, Australia and the Pacific, with its particular type ranging from place to place. Coral will vary widely in habitat from shallow 3-5ft soft coral waters to deep hard coral found over 1000m underwater. The most precious coral for jewellery is the red coral of the Mediterranean, originally found 100ft under water by early fishermen.

This precious coral was thought to be extinct until divers located caves as shallow as 10-12ft containing this red coral species.

Q. So if you’re looking for a piece of jewellery containing red coral, how do you identify it as genuine and not an imitation?

Corals are fairly easy to differentiate with most of the corals – the precious corals – having visible striations that move across the stone/bead. This identifies the growth where the small tree -like structures were with vertical striations of the stems. Many corals are treated with dye to enhance their appearance so being aware of this when purchasing coral is important as those that have been dyed are no longer considered precious. Dyed coral can be identified when a concentrated colour is found along the edges of the stone where the dye has run in a cut stone or if the coral itself is a perfectly uniform colour without imperfection.

Coral value is similar to pearl where the more intense the colour, like red, the more valuable the material is deemed to its pink and orange counterparts.

Q. Final question, I promise! Out of pearl, coral and shell, what is your favourite organic material and why?

That’s a hard one! I have a much more extensive collection of shells since I started collecting them at only 4 years old on the coast which continues till today. In this case, since I’ve been interested for over fifty years, I would probably have to say shells. I collect two main families, the Cowrie shells as well as Conch shells of which The Queen conch is one of them. It was from collecting shells that I got to love pearl, especially as I am yet to find one. The question is tricky as the pearls live inside the shells which then live beside the coral so they are all connected!

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 of Coral Skeleton and Pearl. All images courtesy of Henry Mesa, Latin American Ambassador at Gem-A.


The Fascinating History of Antique Turquoise Jewellery

The Fascinating History of Antique Turquoise Jewellery

In his third Gemstone Conversations column for Gems&Jewellery, Jewellery Historian and Valuer John Benjamin FGA DGA FIRV explores the fascinating history of turquoise and its use in jewellery design from the Shahs of Persia to the Art Deco design movement.

Read more


Birthstone Guide: Garnet For Those Born In January

Birthstone Guide: Garnet For Those Born In January

If you're lucky enough to be born in January, vibrant garnet is your birthstone. A rainbow jewel of the gem world, garnet displays the greatest variety of colour of any mineral and is very often untreated, making it a rarity in the gem world. 

Read more


Getting Started with Quartz Inclusions

Getting Started with Quartz Inclusions

Do you know your calcite inclusions from your dumortierite, epidote, fluorite and rutile? Here, Charles Bexfield FGA DGA EG explores some incredible quartz inclusions and explains what to look for when shopping for quartz specimens.

Read more


Understanding Iridescence: Opals, Pearls, Moonstones and Fractured Stones

Understanding Iridescence: Opals, Pearls, Moonstones and Fractured Stones

Iridescence has to be one of the most mesmerising and magical optical effects seen in gemstones. But have you ever wondered how it occurs? Gem-A's Collection Curator Barbara Kolator FGA DGA shines a light on this fascinating optical effect and tells us about the gems that are most likely to display it.

Read more


Hidden Treasures: Highlights of Gem-A's Gemstones and Minerals Collection

Hidden Treasures: Highlights of Gem-A's Gemstones and Minerals Collection

Gem-A Gemmology Tutor Pat Daly FGA DGA offers us a glimpse at some of the more unusual items in Gem-A's Gemstones and Minerals Collection.

Read more


Tanzanite: The Contemporary December Birthstone

Tanzanite: The Contemporary December Birthstone

Are you looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers tanzanite – one of three birthstones for December – and shares how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Birthstone Guide: Turquoise For Those Born In December

Birthstone Guide: Turquoise For Those Born In December

Beautiful blue turquoise is one of three birthstones for the month of December (in addition to zircon and tanzanite). It is enriched with real cultural significance that can be traced back thousands of years. Here, we explore the blue shades of turquoise and explain what makes this gemstone so special...

Read more


Understanding the Cat's Eye Effect in Gemstones

Understanding the Cat's Eye Effect in Gemstones

Chatoyancy is the gemmological name given to the curious optical effect in which a band of light is reflected in cabochon-cut gemstones, creating an appearance similar to light bouncing off a cat's eye. Gem-A's Collection Curator, Barbara Kolator FGA DGA explains chatoyancy and highlights some of the many gems in which it can occur.

Read more


Jade and its Importance in China

Jade and its Importance in China

Jade has long been revered by gem lovers internationally, but nowhere more so than in China. But what is it that makes this gemstone so special? Gem-A's Assistant Gemmology Tutor Dr Juliette Hibou FGA gives us an overview of jade, how to identify it and its significance in Chinese culture.

Read more


Highlights of Gem-A Conference 2019

Highlights of Gem-A Conference 2019

The Gem-A Conference is always the highlight of our gemmological calendar! If you didn’t manage to make it, we’ve put together a few of the highlights from this year’s event to fill you in on what you missed, and whet your appetite for Gem-A Conference 2020!

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Rio Tinto Reveals The 2.11ct Argyle Everglow Red Diamond

It is always an exciting time of year when Rio Tinto unveils what has been discovered at its Argyle diamond mine. Typically, this is beautiful pink diamonds, with the occasional purplish violet tones. Even rarer still are the fancy red diamonds, which remain a mysterious quantity even today. 

It is without doubt that red diamonds are some of the most beautiful and captivating gemstones, largely due to their extreme rarity. In fact, it has been estimated that as few as 30% of all red diamonds have been discovered, leaving many curious to what showstoppers remain untouched below the surface.

The colour red is thought to symbolise love, passion and strength, which makes red diamonds an especially meaningful shade for collectors with significant funds. Those with an eye on the market will undoubtedly have spotted The Argyle Everglow - a 2.11 carat polished radiant-cut diamond presented as part of the 2017 Argyle Pink Diamonds Tender. 

Read more: The World's Most Expensive Diamond at Auction.

The Argyle Everglow was immediately identified for its miraculous size, colour and clarity and, after being assessed by the Gemological Institute of America (GIA), it has been given a grade of Fancy Red VS2.

Just to put the significance of this into perspective, in the 22-year history of the Argyle Pink Diamonds Tender, there have been less than 20 carats of fancy red certified diamonds sold.  

Argyle Everglow 2.11 carat radiant shaped Fancy Red. Image by Rio Tinto.

The 2017 Argyle Pink Diamonds Tender, also named 'Custodians of Rare Beauty' will present 58 diamonds with a total carat weight of 49.39 carats, including four fancy red diamonds, four purplish red diamonds, two violet diamonds, and one blue diamond.

The five 'hero' diamonds in the collection are as follows:

  • The Argyle Everglow, 2.11 carat radiant shaped fancy red diamond
  • The Argyle Isla, 1.14 carat radiant shaped fancy red diamond
  • The Argyle Avaline, 2.42 carat cushion shaped fancy purple-pink diamond
  • The Argyle Kalina, 1.50 carat oval shaped fancy deep pink diamond
  • Argyle Liberté, 0.91 carat radiant shaped fancy deep grey-violet diamond

 

Argyle Avaline 2.42 carat cushion shaped fancy purple pink. Image by Rio Tinto.

Read more: 'Diamonds: Rare Brilliance' Showcase Collection.

Found primarily in Australia, Africa and Brazil, red diamonds are so rare that only 20 to 30 stones are officially known to exist with each one measuring less than half a carat on average.

Argyle Liberte 0.91 carat radiant shaped fancy deep gray violet. Image by Rio Tinto.

Argyle Kalina 1.50 carat oval shaped fancy deep pink. Image by Rio Tinto.

In light of the reveal of The Argyle Everglow, we hit the archives to recall the most spectacular discoveries of red diamonds that have captured the interest of high-end jewellers, aficionados and collectors worldwide...

The Hancock Red Diamond

Whilst this round brilliant-cut diamond is not famous for its size, weighing in at 0.95ct, it is praised for its astounding deep red and purple colours, making it one of the most highly sought-after stones to date.

The Kazanjian Red

With a history nearly as big as its size, this South African diamond, although later cut in the Netherlands, was found over 100 years ago weighing in at 5.05 carats from the original rough 35ct stone. In 2010, the Kazanjian red diamond was on display in the Morgan Memorial Hall of Gems at the American Museum of Natural History before being purchased by Kazanjian Bros. Inc.

The Moussaieff Red Diamond

Discovered by a Brazilian farmer in the 1990s, the Moussaieff Red, otherwise known as 'Red Shield' is an internally flawless, triangular brilliant-cut fancy diamond famous for its 5.11 carat weight. This iconic diamond remains one of the largest red diamond discoveries in the world to date.

The Edcora Red

This pear-cut fancy red brown diamond, weighing in at 5.71 carats is known as the 'lost stone' due to vanishing from the public eye into the collection of a private investor. Whilst there have been no identified photographs of this red diamond, its existence has been well-documented in writing.

The DeYoung Red Diamond

The DeYoung red diamond is a rare 5.03 carat unmounted diamond purchased by a Boston jewellery seller at a flea market. Sydney DeYoung initially mistook the stone for a garnet but, upon noticing its high quality, had it laboratory tested to reveal its true identity as a red diamond. After his death in 1986, the DeYoung red diamond was given to the Smithsonian Institution’s Natural Gem and Mineral Collection where it remains on public display.   

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 2017 Argyle Pink Diamonds Tender hero diamonds from Rio Tintos Argyle Diamond mine. ©Rio Tinto.


The Fascinating History of Antique Turquoise Jewellery

The Fascinating History of Antique Turquoise Jewellery

In his third Gemstone Conversations column for Gems&Jewellery, Jewellery Historian and Valuer John Benjamin FGA DGA FIRV explores the fascinating history of turquoise and its use in jewellery design from the Shahs of Persia to the Art Deco design movement.

Read more


Birthstone Guide: Garnet For Those Born In January

Birthstone Guide: Garnet For Those Born In January

If you're lucky enough to be born in January, vibrant garnet is your birthstone. A rainbow jewel of the gem world, garnet displays the greatest variety of colour of any mineral and is very often untreated, making it a rarity in the gem world. 

Read more


Getting Started with Quartz Inclusions

Getting Started with Quartz Inclusions

Do you know your calcite inclusions from your dumortierite, epidote, fluorite and rutile? Here, Charles Bexfield FGA DGA EG explores some incredible quartz inclusions and explains what to look for when shopping for quartz specimens.

Read more


Understanding Iridescence: Opals, Pearls, Moonstones and Fractured Stones

Understanding Iridescence: Opals, Pearls, Moonstones and Fractured Stones

Iridescence has to be one of the most mesmerising and magical optical effects seen in gemstones. But have you ever wondered how it occurs? Gem-A's Collection Curator Barbara Kolator FGA DGA shines a light on this fascinating optical effect and tells us about the gems that are most likely to display it.

Read more


Hidden Treasures: Highlights of Gem-A's Gemstones and Minerals Collection

Hidden Treasures: Highlights of Gem-A's Gemstones and Minerals Collection

Gem-A Gemmology Tutor Pat Daly FGA DGA offers us a glimpse at some of the more unusual items in Gem-A's Gemstones and Minerals Collection.

Read more


Tanzanite: The Contemporary December Birthstone

Tanzanite: The Contemporary December Birthstone

Are you looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers tanzanite – one of three birthstones for December – and shares how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Birthstone Guide: Turquoise For Those Born In December

Birthstone Guide: Turquoise For Those Born In December

Beautiful blue turquoise is one of three birthstones for the month of December (in addition to zircon and tanzanite). It is enriched with real cultural significance that can be traced back thousands of years. Here, we explore the blue shades of turquoise and explain what makes this gemstone so special...

Read more


Understanding the Cat's Eye Effect in Gemstones

Understanding the Cat's Eye Effect in Gemstones

Chatoyancy is the gemmological name given to the curious optical effect in which a band of light is reflected in cabochon-cut gemstones, creating an appearance similar to light bouncing off a cat's eye. Gem-A's Collection Curator, Barbara Kolator FGA DGA explains chatoyancy and highlights some of the many gems in which it can occur.

Read more


Jade and its Importance in China

Jade and its Importance in China

Jade has long been revered by gem lovers internationally, but nowhere more so than in China. But what is it that makes this gemstone so special? Gem-A's Assistant Gemmology Tutor Dr Juliette Hibou FGA gives us an overview of jade, how to identify it and its significance in Chinese culture.

Read more


Highlights of Gem-A Conference 2019

Highlights of Gem-A Conference 2019

The Gem-A Conference is always the highlight of our gemmological calendar! If you didn’t manage to make it, we’ve put together a few of the highlights from this year’s event to fill you in on what you missed, and whet your appetite for Gem-A Conference 2020!

Read more


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An Interview with Diamond Artist Angie Crabtree

Painter Angie Crabtree has built a reputation as one of the most sought-after diamond artists, literally recreating every sparkling facet in incredible detail. Here, she shares her passion for painting gemstones (and the occasional watch movement) with Gems&Jewellery...

With the job title 'Diamond Portrait Artist', Angie Crabtree has turned the facets of diamonds and gemstones into a thriving career. Her up-close-and-personal diamond paintings are flying off their easels, while Angie herself is in hot-demand for in-person event appearances and brand collaborations. Here Gems&Jewellery gets to the bottom of her fascinating career in the world of fine jewellery and precious gems...

What is your background and how did you begin painting diamonds?

My background is in art. I have been painting since I was four years old. I went to an arts high school and graduated from the San Francisco Art Institute in 2009. I also attended the School of the Art Institute Chicago and the Rietveld Academie in Amsterdam. I painted my first diamond - at 1.5m tall - in 2013 for a luxury-themed gallery exhibition in San Francisco.

Having known very little about diamond at the time, I began researching and found out that diamonds come in different cuts. This is where my continuous series of diamonds began!

What is it about diamond that has held your attention for so long?

Painting diamond portraits is meditative. I love learning about each one, and I love the abstract patterns and geometry. It's hypnotising! The symmetry, rainbow accents and reflections are so alluring. Every diamond is unique and presents a new challenge.

 How do people react to your work?

When I do live painting at special events, it is a great conversation starter. A handful of companies have commissioned me to paint their special stones, and invited me to paint at their event. Having a stone painted is a great way to show people the details in an up-close and personal way.

Where do you see your paintings progressing - will you be moving into coloured gemstones?

Absolutely yes! I recently started a series of fancy coloured diamonds behind-the-scenes, which I will be releasing sometime in the next year. Eventually, I will work my way to other gemstones and I really cannot wait. Recently I started painting close-ups of very detailed and unique timepieces. They are a new challenge, so I am excited to do more.

What can you tell us about the process of painting a diamond? Do you think people presume it is easier than it appears?

There is a lot that goes into the process that people cannot see just from looking at my Instagram account. Choosing the diamond, having it photographed, drawing the diamond, building the canvas, prepping the canvas, mixing the paint, base coats, layering, glazing, and weeks of drying time between coats. Even the photography is a big step; capturing the essence of my paintings - the exact colours and details - is no easy task.

Why do you think people are so enamoured with your diamond portraits?

I think people are initially interested in my work because diamonds are luxurious, but when they see them as painted works of art they become mesmerised in a new way. At least that is what drew me into the idea of painting them.

Originally, I was interested in exploring ideas of luxury through art, but after researching diamonds and gemmology, the whole series went in a new direction: it became more about getting lost in the abstract patterns, facets, reflections and colours - similar to how I fee; when I look into a kaleidoscope.

Are there any particular pieces you are most proud of?

My favourite piece is the painting I did of my engagement ring diamond. It is of an elongated emerald-cut that I picked out from my friends at Perpetuum Jewels in San Francisco. When I was searching for the perfect diamond, I knew it would eventually become a painting, so that is why I chose this one: I wanted to have a panoramic piece to hang in our home. It is the only piece I will never sell. I recently began selling phone cases printed with the diamond because, why not?! It is the perfect proportions!

What would be your advice to amateur artists who want to give painting diamonds and gemstones a try?

My advice would be to focus on not just the symmetry of the design, but also balancing of the colours and contrast. Mix all your colours from scratch so that they are in their purest form. Quality materials are important too.

Gem-A members can log in to read the full article Gems&Jewellery Autumn 2017 / Volume 26 / No. 3

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: Angie Crabtree with a selection of her diamond paintings. All images © Angie Crabtree.

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Graff Diamonds buys 1,109ct Lesedi La Rona Diamond for $53m

The second largest gem-quality diamond ever discovered has been sold privately to Graff Diamonds for a staggering $53 million. 

First unearthed by the Lucara Diamond Corporation in the Karowe mine in Botswana, the Type IIa Lesedi La Rona diamond weighs in at 1,109 carats. It was initially put up for auction in June 2016, but after failing to reach its pre-sale estimate of $70m, stalling at $61m, the diamond was hidden away. 

Graff has a long-running reputation for buying big diamonds, including a 373 carat rough believed to be a fragment of the Lesedi La Rona in May 2017. The price was a cool $17.5m. 

Read more: Magnificent 51ct Dynasty Diamond Unveiled by Russian Mining Giant

The Karowe mine is also where the 813 carat Constellation diamond was uncovered in 2015. This particular diamond holds the record as being the world's most expensive, having been sold for $63m to a Dubai-based company. It is now in the hands of de Grisogono founder, Fawaz Gruosi, who is transforming the rough into as-yet-undisclosed masterpieces. 


Whilst the Lesedi La Rona diamond failed to sell at auction, it has now been privately sold to Graff Diamonds for $53m. ©Graff Diamonds


The 1,109-carat Lesedi La Rona is the second largest diamond in the world. ©2017 Lucara Diamond Corp.

Commenting on the purchase, Graff Diamonds founder and chairman, Laurence Graff, commented: "We are thrilled and honoured to become the new custodians of this incredible diamond. The stone will tell us its story, it will dictate how it wants to be cut, and we will take the upmost care to respect its exceptional properties. This is a momentous day in my career, and I am privileged to be given the opportunity to honour the magnificent natural beauty of Lesedi La Rona."

Lucara president and CEO, William Lamb, called the discovery of the stone a "company-defining event". He noted: "We took our time to find a buyer who would take the diamond through its next stage of evolution. Graff Diamonds is now the owner of the Lesedi La Rona as well as the 373-carat diamond... We are excited to follow these diamonds through the next stage of their journey."

High jewellery aficionados will now have to wait patiently to see what Graff Diamonds does with this incredible rough. 

Read more: Extraordinary emerald valued at $309 million is unearthed in Brazil

For further information and photos of the Lesedi La Rona visit lucaradiamond.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.

Cover image: The 1,109-carat Lesedi La Rona diamond sold to Graff Diamonds. ©2017 Lucara Diamond Corp.


The Fascinating History of Antique Turquoise Jewellery

The Fascinating History of Antique Turquoise Jewellery

In his third Gemstone Conversations column for Gems&Jewellery, Jewellery Historian and Valuer John Benjamin FGA DGA FIRV explores the fascinating history of turquoise and its use in jewellery design from the Shahs of Persia to the Art Deco design movement.

Read more


Birthstone Guide: Garnet For Those Born In January

Birthstone Guide: Garnet For Those Born In January

If you're lucky enough to be born in January, vibrant garnet is your birthstone. A rainbow jewel of the gem world, garnet displays the greatest variety of colour of any mineral and is very often untreated, making it a rarity in the gem world. 

Read more


Getting Started with Quartz Inclusions

Getting Started with Quartz Inclusions

Do you know your calcite inclusions from your dumortierite, epidote, fluorite and rutile? Here, Charles Bexfield FGA DGA EG explores some incredible quartz inclusions and explains what to look for when shopping for quartz specimens.

Read more


Understanding Iridescence: Opals, Pearls, Moonstones and Fractured Stones

Understanding Iridescence: Opals, Pearls, Moonstones and Fractured Stones

Iridescence has to be one of the most mesmerising and magical optical effects seen in gemstones. But have you ever wondered how it occurs? Gem-A's Collection Curator Barbara Kolator FGA DGA shines a light on this fascinating optical effect and tells us about the gems that are most likely to display it.

Read more


Hidden Treasures: Highlights of Gem-A's Gemstones and Minerals Collection

Hidden Treasures: Highlights of Gem-A's Gemstones and Minerals Collection

Gem-A Gemmology Tutor Pat Daly FGA DGA offers us a glimpse at some of the more unusual items in Gem-A's Gemstones and Minerals Collection.

Read more


Tanzanite: The Contemporary December Birthstone

Tanzanite: The Contemporary December Birthstone

Are you looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers tanzanite – one of three birthstones for December – and shares how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Birthstone Guide: Turquoise For Those Born In December

Birthstone Guide: Turquoise For Those Born In December

Beautiful blue turquoise is one of three birthstones for the month of December (in addition to zircon and tanzanite). It is enriched with real cultural significance that can be traced back thousands of years. Here, we explore the blue shades of turquoise and explain what makes this gemstone so special...

Read more


Understanding the Cat's Eye Effect in Gemstones

Understanding the Cat's Eye Effect in Gemstones

Chatoyancy is the gemmological name given to the curious optical effect in which a band of light is reflected in cabochon-cut gemstones, creating an appearance similar to light bouncing off a cat's eye. Gem-A's Collection Curator, Barbara Kolator FGA DGA explains chatoyancy and highlights some of the many gems in which it can occur.

Read more


Jade and its Importance in China

Jade and its Importance in China

Jade has long been revered by gem lovers internationally, but nowhere more so than in China. But what is it that makes this gemstone so special? Gem-A's Assistant Gemmology Tutor Dr Juliette Hibou FGA gives us an overview of jade, how to identify it and its significance in Chinese culture.

Read more


Highlights of Gem-A Conference 2019

Highlights of Gem-A Conference 2019

The Gem-A Conference is always the highlight of our gemmological calendar! If you didn’t manage to make it, we’ve put together a few of the highlights from this year’s event to fill you in on what you missed, and whet your appetite for Gem-A Conference 2020!

Read more


 

Additional Info

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Survivors - The Geology of Diamonds

From the Spring 2018 issue of Gems&Jewellery magazine, Gem-A assistant tutor Beth West FGA DGA explores the remarkably epic journey of diamonds and how their characteristic strength is rooted in their archaic origins.

"In the deep glens where they lived all things were older than man and they hummed of mystery."
Cormac McCarthy, The Road

Carbon is the fourth most abundant element in the universe. It is one of life’s most important building blocks. We are made up of around 18% carbon. The diamond, however, is formed of pure carbon and bonded in such a way as to make it the earth’s hardest naturally occurring substance.

But these magnificent gems extend far beyond their beauty and durability; they carry whispers of the beginnings of our world.

How old is a diamond?

It has been proven that the oldest diamonds formed around 3.5 billion years ago in an age known as the Archean Eon. At this point, it is believed that the planet had only existed for around 1 billion years. The surface of the earth was still settling.

How are they formed?

The earth is formed in layers. The outer most layer is known as the crust and ranges between 6km and 40km deep. It is divided into the thicker continental crust, making up the landmass, and oceanic crust – the ocean floors. Beneath the crust is the mantle. It accounts for eight tenths of the earth’s volume and is predominantly composed of an igneous rock known as peridotite.

The upper most portion of the mantle and the crust are known as the lithosphere (‘rocky sphere’ in Greek). This part of the earth is rigid, whereas the deeper parts of the mantle are in a permanent state of convection as the rock melts and cools. At the centre of the earth, the liquid core encases the solid inner core – the 5500° C iron and nickel heart.

In the Archean Eon, as the crust shifted and split, portions of it found their place and settled. These archaic, unmoving pieces of crust are known as ‘cratons’. Under each craton is a root or keel of lithospheric mantle that can descend up to 300 kilometres deep. These keels are cooler than the neighbouring convecting mantle, at around 1200° C at its deeper points.

Diamond will start to form at around that temperature if the corresponding pressure is around 40000 atmospheres. That equates to a depth of around 140km. These deep lithospheric keels beneath the cratons, away from the chaos of the convecting mantle, were perfect safe-houses for a growing diamond.

Petra Diamonds' South African Mine, Finsch. Showing open put with subsequent block cave extraction, tunnels visible.
Image by Charles Evans FGA DGA.

Where did the carbon come from?

The carbon would have derived from either a primordial source (extant from the birth of the earth) or from material pulled into the mantle when the ocean floor was pushed beneath colliding continental crust.

The carbon would have been locked into compounds such as methane (CH4) or carbonates (CO3) travelling in melts or fluids around the convecting mantle. When these fluids passed through the mantle keel, they would have reacted to the peridotite, freeing the carbon from their compounds and allowing it to crystallise as diamond. It is in these deep portions of the keel that the oldest diamonds formed.

How did they get to us?

They resided in the keel for millions of years until, around the age of the dinosaurs (between an approximate age of 300 and 80 million years old), they were expelled from their plutonic residence via forceful, violent eruptions of magma produced deep in the mantle.

Kimberlite is the most abundant of the three types of known diamond bearing magma. This powerful magma blasted through to the surface producing a cone shaped hole called a ‘pipe’. Those diamonds that were carried up with the blast were left shaken but intact in the magmatic debris that packed the hole or were forced to travel with the weathering surface of the earth – often for great distances, in rivers or in glaciers, and for millions of years.

From the depths of the earth to the ring on our fingers, these stones have certainly proved their strength. So when we are drenched by the sparkle and marketed bling of these gemstones, it is perhaps worth remembering their remarkable journey.

This article originally appeared in Gems&Jewellery Spring 2018/ Volume 27/ No.1 

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: Diamond Crystal. Image by Pat Daly


The Fascinating History of Antique Turquoise Jewellery

The Fascinating History of Antique Turquoise Jewellery

In his third Gemstone Conversations column for Gems&Jewellery, Jewellery Historian and Valuer John Benjamin FGA DGA FIRV explores the fascinating history of turquoise and its use in jewellery design from the Shahs of Persia to the Art Deco design movement.

Read more


Birthstone Guide: Garnet For Those Born In January

Birthstone Guide: Garnet For Those Born In January

If you're lucky enough to be born in January, vibrant garnet is your birthstone. A rainbow jewel of the gem world, garnet displays the greatest variety of colour of any mineral and is very often untreated, making it a rarity in the gem world. 

Read more


Getting Started with Quartz Inclusions

Getting Started with Quartz Inclusions

Do you know your calcite inclusions from your dumortierite, epidote, fluorite and rutile? Here, Charles Bexfield FGA DGA EG explores some incredible quartz inclusions and explains what to look for when shopping for quartz specimens.

Read more


Understanding Iridescence: Opals, Pearls, Moonstones and Fractured Stones

Understanding Iridescence: Opals, Pearls, Moonstones and Fractured Stones

Iridescence has to be one of the most mesmerising and magical optical effects seen in gemstones. But have you ever wondered how it occurs? Gem-A's Collection Curator Barbara Kolator FGA DGA shines a light on this fascinating optical effect and tells us about the gems that are most likely to display it.

Read more


Hidden Treasures: Highlights of Gem-A's Gemstones and Minerals Collection

Hidden Treasures: Highlights of Gem-A's Gemstones and Minerals Collection

Gem-A Gemmology Tutor Pat Daly FGA DGA offers us a glimpse at some of the more unusual items in Gem-A's Gemstones and Minerals Collection.

Read more


Tanzanite: The Contemporary December Birthstone

Tanzanite: The Contemporary December Birthstone

Are you looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers tanzanite – one of three birthstones for December – and shares how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Birthstone Guide: Turquoise For Those Born In December

Birthstone Guide: Turquoise For Those Born In December

Beautiful blue turquoise is one of three birthstones for the month of December (in addition to zircon and tanzanite). It is enriched with real cultural significance that can be traced back thousands of years. Here, we explore the blue shades of turquoise and explain what makes this gemstone so special...

Read more


Understanding the Cat's Eye Effect in Gemstones

Understanding the Cat's Eye Effect in Gemstones

Chatoyancy is the gemmological name given to the curious optical effect in which a band of light is reflected in cabochon-cut gemstones, creating an appearance similar to light bouncing off a cat's eye. Gem-A's Collection Curator, Barbara Kolator FGA DGA explains chatoyancy and highlights some of the many gems in which it can occur.

Read more


Jade and its Importance in China

Jade and its Importance in China

Jade has long been revered by gem lovers internationally, but nowhere more so than in China. But what is it that makes this gemstone so special? Gem-A's Assistant Gemmology Tutor Dr Juliette Hibou FGA gives us an overview of jade, how to identify it and its significance in Chinese culture.

Read more


Highlights of Gem-A Conference 2019

Highlights of Gem-A Conference 2019

The Gem-A Conference is always the highlight of our gemmological calendar! If you didn’t manage to make it, we’ve put together a few of the highlights from this year’s event to fill you in on what you missed, and whet your appetite for Gem-A Conference 2020!

Read more


 

Additional Info

Read more...

An Afternoon in Antwerp's Historic Diamond District

Gem-A Member Carmen Garcia-Carballido MSc., L. Geology, EurGeol FGA DGA, explores Antwerp's historic diamond district - the Diamantkwartier.

Antwerp in Belgium is famous for diamonds. In 2017, it traded approximately 234 million carats. Over 80% of rough diamonds are purchased in Antwerp, where half the world’s 'Kimberley Certificates' are issued, and the square mile of its 'Diamond Quarter' hosts 1,600 diamond dealers, employing over 30,000 people. Diamond, not beer, is Belgium's top export.

Antwerp History 

In the 16th century, Antwerp was the world’s biggest trade centre, with the diamond trade to and from the city having been recorded since 1447.

Port House of Antwerp, Belgium. Designed by Zaha Hadid, which reinterprets Antwerp's moniker as the city of diamond.
Image Credit: pixabay
 

But how are diamonds traded? It started in the coffee houses near Centraal Station. In the days before security cameras, merchants had to move fast to avoid being mugged, so the 'Diamond Quarter' sprang up just next to the station, which is still a convenient location for tourists and dealers. Nowadays, vetted and registered members can trade at one of Antwerp’s four diamond bourses; there is no other city in the world with so many, and there are only 30 Diamond Bourses worldwide. Some bourses specialise in cut diamonds, others in rough or industrial diamonds and some are even on the sites of the old coffee houses. 

Antwerp Centraal Station. Image Credit: pixabay 

The Antwerp World Diamond Centre (AWDC), a private foundation representing the sector in Belgium, maintains Antwerp’s position as a world diamond centre. Antwerp's main diamond bourse was founded in 1904 and by WWII it had 1,645 members, however, at the war’s end just 335 remained. The AWDC hosts the 'Diamond Office' founded in 1945 to encourage Jewish diamantaires to return to Antwerp, and it also now handles all diamonds entering the city. 

Dealing in diamonds is an expensive business. A tender facility located within the AWDC is where mining companies sell their rough diamonds. Each buyer bids in a sealed envelope and the stones are sold to the highest bidder. Specialised banks give fast credit to registered trading companies and all transactions are by bank transfer to comply with anti-fraud laws.Although diamond dealing is based on trust, diamond bourse members must comply with strict rules.

History of Antwerp and Diamond Cutting 

Antwerp has a rich history of diamond cutting. Marcel Tolkowsky, a native of Antwerp, refined the brilliant cut early in the 20th century. His nephew, Gaby Tolkowsky, cut some of the world’s most famous diamonds: the Centenary (273.85 ct) and the Golden Jubilee (545.7 ct). Until the early 1970s, most rough diamonds traded in Antwerp were also cut there.

Nowadays, rough is exported to India or China for cutting and polishing and re-imported for sale in Antwerp, hence the saying: "Almost every diamond in the trade travels though Antwerp at least once." 

 Figure 1

I visited the fantastic showroom at DiamondLand (Appelmansstraat 33) and saw cutters and polishers at work. Figure 1 shows a crossworker using the traditional equipment, including; the scaife, a horizontal cast iron disc which rotates at 3,200 rpm and is impregnated with diamond dust and oil; an adjustable dop which holds the diamond; and the tang, a tripod which holds the dop. 

 
Figure 1a

The tang is held by the crossworker who exerts pressure onto the diamond while cutting and polishing. It is lifted frequently to inspect the diamond under the loupe, and here two diamonds are being worked at the same time (Fig. 1a).

Royal 201 Diamonds

DiamondLand also showed me some Royal 201 cut diamonds. This modification of the round modern brilliant cut has been on the market circa 2004. It has 65 crown and 40 pavilion facets plus 96 micro facets on the girdle. The Royal 201 cut exhibits higher brilliance and fire than the modern brilliant cut and this can affect colour grading, making a Royal 201 cut stone appear a higher colour grade than it really is. It has different proportions to the modern brilliant cut; the crown appears bulgier, so it is important that diamond graders and valuers identify this cut and put it in its context.

Before leaving the Diamond Quarter, I paid a visit to HDR Antwerp, a famous institution for diamond certification, training, and instruments (both gemmological and for diamond manufacture and screening) where I had the opportunity to see their range of state-of-the-art devices. So, Gem-A members, if you happen to find yourselves in Antwerp, take a moment to explore its rich diamond history.

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.

Additional Info

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Delving into Diamonds: Gem-A President and Diamond Expert, Eric Bruton

There is one name in gemmological science that is synonymous with the study of Diamonds: BRUTON. Studying under the genius of Basil Anderson and Robert Webster, Eric Bruton had such an impact on the gemmological world that his work forms the basis of Gem-A’s Diamond Diploma to this day.

Born in London in 1915, Bruton started a career in publishing before joining the engineering branch of the RAF during World War II, where he was in charge of technical training and also served in India.

Eric Bruton ©Gem-A

On returning to the UK, Bruton was invited to edit four prominent publications: Industrial Diamond Review, Horological Journal, Goldsmiths’ Journal and – importantly for Gem-A – The Gemmologist, published by the National Association of Goldsmiths (NAG). Bruton immediately signed up for classes at Chelsea Polytechnic – then being led by Anderson and Webster – and began what would become a life-changing adventure into the world of gemmology.

READ MORE: Speaker in the Spotlight, Peter Lyckberg

Eric Bruton was awarded his Gemmology Diploma in 1950, and began teaching for the Association in 1967 – specialising in diamonds, running courses at St John Cass College London, and a similar course at Barcelona University – with examinations by The Gemmological Association of Great Britain. All of this was building up to Bruton’s breakthrough publication, his first practical handbook in 1970: Diamonds.

Until Diamonds, books on this subject were either highly technical or focused on one particular aspect of the industry. Recognising this problem, Bruton’s response was to cover all aspects of gem diamonds, spanning the history of diamond, mining and recovery, cutting methods, grading and valuation, and the identification of diamond and its simulants.

READ MORE: Investigating Fake Rough 

Throughout his research and his travels to various diamond mines across the world, Bruton realised that the various compartments of the diamond industry had little – or indeed no – knowledge of their counterparts. Most important of all, members of the public did not ‘appreciate that the possession of a diamond…has taken 4000 years of endeavour – blood, toil, sweat and tears – to produce the modern brilliant-cut diamond’ (viii).

Bruton was the ideal person to address this – with his editorial experience and gemmological expertise, he was in a rare and strong position to deliver.

Eric Bruton by David Langdon, 1971. Image Credit: Gem-A. 

Bruton’s Diamonds is a systematic study of all aspects of diamonds and forms the foundation of Gem-A’s Diamond Diploma. For many years, Bruton specialised in writing on all matters relating to gems, jewellery, and watches – and  even crime fiction! Bruton also founded the trade’s only newspaper of the time – Retail Jeweller – which, in competition with Watchmaker Jeweller & Silversmith - became the voice of the trade, and in 1994 was elected president of the Association.

READ MORE: Heritage Series, Let's Bragg About It! 


Today, Bruton’s contribution to the Gem-A is remembered with the Bruton Medal, a prize awarded to exceptional students with the best results in the Diamond Diploma examination, and the Bruton Room at Gem-A HQ in London, where future gemmologists study diamonds.

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: Diamond Crystal Trigons, photo by Pat Daly, with Bruton Medal. Image by Gem-A. 


The Fascinating History of Antique Turquoise Jewellery

The Fascinating History of Antique Turquoise Jewellery

In his third Gemstone Conversations column for Gems&Jewellery, Jewellery Historian and Valuer John Benjamin FGA DGA FIRV explores the fascinating history of turquoise and its use in jewellery design from the Shahs of Persia to the Art Deco design movement.

Read more


Birthstone Guide: Garnet For Those Born In January

Birthstone Guide: Garnet For Those Born In January

If you're lucky enough to be born in January, vibrant garnet is your birthstone. A rainbow jewel of the gem world, garnet displays the greatest variety of colour of any mineral and is very often untreated, making it a rarity in the gem world. 

Read more


Getting Started with Quartz Inclusions

Getting Started with Quartz Inclusions

Do you know your calcite inclusions from your dumortierite, epidote, fluorite and rutile? Here, Charles Bexfield FGA DGA EG explores some incredible quartz inclusions and explains what to look for when shopping for quartz specimens.

Read more


Understanding Iridescence: Opals, Pearls, Moonstones and Fractured Stones

Understanding Iridescence: Opals, Pearls, Moonstones and Fractured Stones

Iridescence has to be one of the most mesmerising and magical optical effects seen in gemstones. But have you ever wondered how it occurs? Gem-A's Collection Curator Barbara Kolator FGA DGA shines a light on this fascinating optical effect and tells us about the gems that are most likely to display it.

Read more


Hidden Treasures: Highlights of Gem-A's Gemstones and Minerals Collection

Hidden Treasures: Highlights of Gem-A's Gemstones and Minerals Collection

Gem-A Gemmology Tutor Pat Daly FGA DGA offers us a glimpse at some of the more unusual items in Gem-A's Gemstones and Minerals Collection.

Read more


Tanzanite: The Contemporary December Birthstone

Tanzanite: The Contemporary December Birthstone

Are you looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers tanzanite – one of three birthstones for December – and shares how this relatively new gemstone compares to its purple and blue-hued rivals.

Read more


Birthstone Guide: Turquoise For Those Born In December

Birthstone Guide: Turquoise For Those Born In December

Beautiful blue turquoise is one of three birthstones for the month of December (in addition to zircon and tanzanite). It is enriched with real cultural significance that can be traced back thousands of years. Here, we explore the blue shades of turquoise and explain what makes this gemstone so special...

Read more


Understanding the Cat's Eye Effect in Gemstones

Understanding the Cat's Eye Effect in Gemstones

Chatoyancy is the gemmological name given to the curious optical effect in which a band of light is reflected in cabochon-cut gemstones, creating an appearance similar to light bouncing off a cat's eye. Gem-A's Collection Curator, Barbara Kolator FGA DGA explains chatoyancy and highlights some of the many gems in which it can occur.

Read more


Jade and its Importance in China

Jade and its Importance in China

Jade has long been revered by gem lovers internationally, but nowhere more so than in China. But what is it that makes this gemstone so special? Gem-A's Assistant Gemmology Tutor Dr Juliette Hibou FGA gives us an overview of jade, how to identify it and its significance in Chinese culture.

Read more


Highlights of Gem-A Conference 2019

Highlights of Gem-A Conference 2019

The Gem-A Conference is always the highlight of our gemmological calendar! If you didn’t manage to make it, we’ve put together a few of the highlights from this year’s event to fill you in on what you missed, and whet your appetite for Gem-A Conference 2020!

Read more


 

Additional Info

Read more...

婚約指輪に使われたダイヤモンドの歴史

 

ジャック・オグデンFGAが、婚約指輪に使われていたダイヤモンドの歴史について見ていきます 。この習慣がどれほど古いものなのか、少し驚くかもしれません...

ここで皆さんに質問があります。婚約指輪に関する次の文章を読んでください。「婚約指輪に は、250から2000ドルと価格に幅があるが、現代ファッションにおいてはダイヤモンドのソリテ ール(一石のダイヤモンドを留めたリング)と定める」。これがいつ書かれたものであると思 いますか?第二次世界大戦の前でしょうか、後でしょうか?

Additional Info

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Buying Guide: Coloured Diamonds from Least to Most Valuable

The typical image of a diamond tends to be of a clear and colourless stone, therefore it is hardly surprising that these are presumed to have the highest monetary value. In reality, diamonds can present as a range of different colours and uniquely-coloured diamonds can command premium prices.

Coloured diamonds are created when impurities or deformities occur in a diamond’s lattice of carbon atoms, with particular impurities resulting in different colour formations.

The most valuable stones will be those which are purest in colour, most saturated and most even in tone. In order to assess the grades of colour, coloured diamonds are placed into one of nine categories: faint (least valuable), very light, light, fancy light, fancy, fancy dark, fancy intense, fancy deep and fancy vivid (the rarest and most expensive).

The Aurora Pyramid of Hope collection polished diamondsThe Aurora Pyramid of Hope Collection contains the full spectrum of natural diamond colours.
Image copyright Trustees of NHM, London.

Increasing rarity leads to higher retail prices and by examining the variations between some notable types of coloured diamonds, we can see a clear scale of value emerging based on an agreed-upon grading system.

Brown Diamonds

The colouration of brown diamonds is caused by a deformation of the diamond lattice during the gemstone’s growth within or expulsion from the mantle. In fact, 98% of all mined diamonds will have a brown tone, which is generally considered unfavourable. However, thanks to the savvy marketing team at Australia’s Argyle mine, a new trend for ‘cognac’ or ‘champagne’ diamonds emerged in the 1990s.

Yellow Diamonds

Yellow diamonds gain their colour through nitrogen (N) impurities in the diamond lattice. N often finds itself incorporated in the diamond’s atomic structure, as it is similar in size to the carbon atom. If the diamond has been resident in the mantle for a considerable amount of time, the N will aggregate to form a group of three N atoms and a vacancy. This creates a ‘colour centre’ that absorbs light and makes a diamond appear yellow.

Read more: What Makes a Gemstone Rare?

However, the rarest yellow diamonds are the youngest diamonds; in such stones, the N atoms have not joined forces and remain isolated within the diamond’s atomic structure, resulting in the creation of the celebrated ‘canary yellow’. In May 2014 the Graff Vivid Yellow, at a stellar 100.09 carats, brought $16.3 million at Sotheby's.

Pink Diamonds

Similar to brown diamonds, the pink colouration of a diamond is associated with a deformation of the diamond lattice. This would have occurred while it grew deep within the earth’s mantle in areas where tectonic plates collided and mountains formed.

A 1.27 carat fancy intense pink diamondA 1.27 carat fancy intense pink diamond surrounded by eight Argyle fancy intense pink marquise-cut diamonds and 3.36 carats of pear-shape diamonds. Image courtesy of BD Luxury: bdluxury.com

Read more: Discover the Pink Diamonds of the 2018 Argyle Diamond Tender

The Argyle mine in Australia is one of the principal sources for pinks – but they are rare, accounting for only 0.1% of overall production. Testament to its huge popularity, the 18.96ct Winston Pink Legacy diamond fetched a sum of $50,375,000 at Christies in 2018.

Blue Diamonds

The rarest and most sought-after blue diamonds owe their colour to infinitesimal levels of boron impurities and, like canary yellow, account for less than 1% of all natural stones.

Read more: The 6.16 carat Farnese Blue Diamond

Selling for $57,500,000 at Christies in May 2016, the 14.6ct Oppenheimer Blue is the most expensive fancy vivid blue diamond sold to date, and clearly demonstrates that quality blue diamonds can attract premium prices at auction.

Blue diamondAn exceptional 29.6 carat blue diamond recovered at the Cullinan mine, January 2014. Courtesy of Petra Diamonds.

Green Diamonds

The green colouration in diamonds is generally caused by irradiation and the colour is often only skin deep, having occurred in the crust after the gemstone has formed. A natural green diamond of good colour is very rare and highly valuable; the most expensive green diamond ever sold was the 5.03ct Aurora Green for HK $16.8 million at Christie’s in May 2016. However, because it is very difficult to differentiate between natural and artificially irradiated stones, they are treated with caution by the market.

Dresdner Grüner Diamant Neues Grünes Gewölbe DresdenThe Dresden Green Diamond - a 41 carats (8.2 g) natural green diamond, which probably originated in the Kollur mine in the state of Andhra Pradesh in India. Here it is pictured as part of a hat clasp ornament. (By ubahnverleih - Own work, CC0)

Red Diamonds

Red diamonds are somewhat mysterious to researchers, as the cause of their colouration remains yet unknown. Moreover, as only a handful of stones are known, they remain the holy grail of natural coloured diamonds; the largest ever red diamond, the 5.11ct Moussaieff Red diamond, was discovered in Brazil in 1990 and bought by Moussaieff Jewellers in the early 2000s for an estimated $8,000,000.

Other Notable Coloured Diamonds

There are several other varieties of coloured diamonds, however because of their rarity and the fact that they are mostly sold at tender, it is difficult to place a value on them. One interesting example is the chameleon diamond, a diamond which changes colour when exposed to extreme heat or UV light, which is exceedingly unusual but seldom comes to market. 

Read more: The Geology of Diamonds

Grey diamonds gain their colour through hydrogen impurities. Although they are extremely rare, the very fact that they are so unusual means that they have not attracted a great deal of public awareness and have no substantial market desirability. Likewise, violet diamonds are exceptionally rare and hard to value. One of the oldest types of diamonds (type 1 AB), they typically only appear in sizes up to a maximum of 0.25ct and as such larger stones make particularly special finds.

Argyle Isla 1.14 carat radiant shaped Fancy Red Rio Tinto Gem A BlogThe Argyle Isla - a 1.14 carat radiant shaped fancy red diamond. Image courtesy of Rio Tinto. 

As with red diamonds, orange diamonds are very unusual and the origination of their colour has not yet been discovered. The largest ever orange diamond, a 14.82ct pear-shaped fancy vivid orange, stunned at Christie’s in 2013 when it sold for CHF 32,645,000, over double its lower estimate.

By contrast, although white (not clear, but diamonds with a milky-white tone) and black diamonds are quite rare, they have not managed to capture the favour and attention of the public and are considered to be the least valuable of all coloured diamonds.

Interested in furthering your knowledge about diamonds? Find out about Gem-A's Diamond Diploma and Workshops here.

Cover image: Fancy colour diamonds from the Aurora Pyramid of Hope collection - rough and polished diamonds. Copyright Aurora Gems. Photo by Robert Weldon.

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How to Identify Antique Edwardian Jewellery

Understanding how to identify jewellery from different eras and design movements is essential for historians, valuers and antique collectors. Here, Starla Turner FGA GG offers us a glimpse into the refined and elegant world of Edwardian jewellery and describes the motifs that make pieces recognisable. 

Fashion of the Edwardian Era

The short reign of King Edward VII (1901 to 1910), his court, his sporting lifestyle and his wife Alexandra of Denmark were a breath of fresh air to fashion at the close of the 1800s. Jewellery motifs changed accordingly, with intricate and gracefully symmetrical, diamond-encrusted and lacy designs adorning the neckline, chiffon gowns and the ‘up-do’ hair styles of the well-to-do. Delicate scrolls, leaves, ribbon bows, hearts, circles, swooping swags (or garlands as they were later called), and veil-like twinkling jewellery complimented a new sophisticated style.

To me, Edwardian designs look like a frozen moment – curled in movement, shimmering, draping, scrolling, swaging, circling – just waiting to be worn and move again. The Edwardian femininity, fluidity, and fineness are unmistakeable. Iconic pieces have hinges, dangles, swags, articulation, and tiny swinging gemstone droplets evoking a liquidity and liveliness.

Queen Alexandra loved the uncomfortable but fashionable ‘dog collar’ plaque style necklace, often backed by black velvet. The style transitioned into a column of 6-16 rows of pearls — a challenge to wear for sure. Changing dress necklines brought changing neck ornamentation. A good example is the rivière necklace – a neck-encircling strand of graduating, millegraine-edged, bezel set diamonds — sometimes worn as two bracelets.

Read more: The Tale of the Mouawad-Tereschenko Blue Diamond

We see up to 72-inch long strands of ‘spectacle set’ diamonds, a minimalist technique where only a thin wire wraps the diamond girdle and small side jump rings attach to the next gem. The lavaliere is an articulating drop suspended from a matching design element and attached directly to a thin, fancy link chain. The negligee necklace has two drops, often on different lengths of chain, attached to one design element and a simple chain. Basic pendants have diamond-set, double side engraved, tapered bales that hang on thin, intricately designed chains.

Tiaras of the Edwardian Era 

The Edwardian era also saw a fascination with tiaras. Bandeaus, like tiaras, could double as necklaces or bracelets — screw holes or extra loops in the backside show their transitioning versatility. Sautoirs, long bundles of pearl strands ending with tassels, were wrapped around necks, waists, bodices and arms. Bracelets show symmetrical repeating designs in either full length or top half only designs. A new trend was the more diminutive, tapering diamond and coloured stone bracelets with articulating or stretching metal links in the rear. Rings were becoming wider and domed just enough to accommodate the depth of the centre diamond.Edwardian Swan Brooch Back by Lang Antiques Gem A Blog Antique Jewellery VintageThe back of a beautiful swan pin, showing calibré cut emeralds and the 'swinging' diamonds typical of the Edwardian era. 

The Rise of Platinum in Edwardian Jewellery 

Solid platinum or platinum over gold suited the pale, pastel and feminine fashion palette. Platinum was a new white metal that, unlike silver, didn’t stain the skin and clothing and could strongly, but delicately, hold the all-important diamond. Initially, platinum was bonded to yellow gold, a technique created to add value and acceptability to this new, inexpensive and unappreciated metal.

The vast majority of Edwardian diamond pieces I see are hand-fabricated (cut, sawn, rolled, drawn and assembled). Cast pieces are uncommon due to the high heat required to melt the metal. Edwardian jewellery is typically assembled from fewer parts, likely due to the visibility of the yellow gold-based solder that was used.

Read more: The Fascinating History of Platinum Jewellery 

This yellowish solder in seams disappeared into a whiter hue after WWI when white gold made its debut. In addition, platinum is a noble metal – it does not tarnish – so the tarnish one sees is from the solder mix of gold, silver and platinum. Therefore, tarnish and patina can add provenance as it develops with age. Sometimes re-polishing the metal can remove a bit of authenticity.

Diamonds in Edwardian Jewellery 

South Africa supplied a plethora of diamonds. While the Second Boer War (Oct 1899 –May 1902) had an impact on pricing, the demand continued. The diamond circular saw, the fixed dop (the clamp that holds a diamond being cut) for precise angles, bruiting machine advancements and electricity reduced cutting times. They also resulted in the more brilliant, rounder European-cut diamond.

Marquise and pear-shapes also became more available. The beauty of a finished diamond became the focus, rather than the weight retention.

Edwardian Brooch by Lang Antiques Gem A Blog Antique Jewellery VintageAn Edwardian era pin that would have doubled as a tiara or hair ornament. 

Later into the period, single cut diamonds replaced the rose cuts of the past. With faster cutting techniques, the sparkling 17 facet single cut became the perfect accent to delicate jewellery. Smaller Swiss-cut and small European-cut diamonds also help date this era. Old mine cutting was phased out by the end of the era, but diamonds were still recycled into new pieces.

Pearls in Edwardian Jewellery 

Pearls were second to diamond in popularity and suited the monochromatic styling of the era. Their ethereal sheen worked beautifully with gossamer fabrics. Articulating drops gave the appearance of water and added the wonderful element of movement in open work designs. Due to the rarity of natural pearls (cultured pearls were about to debut in high numbers) seed pearls of 3.5mm or smaller were cut into two useable halves and flush mounted onto metal.

Read more: Understanding Diamond Colours with the Aurora Pyramid of Hope 

The American and Scottish freshwater pearls reveal a whiter, wrinkled skin whereas the Indian Ocean and Gulf saltwater pearls are creamy to light grey (often turning grey from a soap that has been used to clean them) and smooth skinned. Uncut and larger natural pearls are often button or oval shaped. The very round cultured pearls in Edwardian pieces tend to be replacement stones.

Gemstones in Edwardian Jewellery 

Sapphire, emerald, opal, ruby, amethyst, demantoid garnet, moonstone or peridots were recessed into a circle of diamonds — enter the halo ring! Look for treasures in these old pieces: Kashmir sapphires, Burmese rubies, Russian demantoid garnets, Australian black opals.

Edwardian Oval Diamond Brooch by Lang Antiques Gem A Blog Antique Jewellery VintageA pierced-out brooch from the Edwardian era.

Calibré cut stones, the tiny (1-2mm), straight-sided, geometrically shaped ruby, sapphire, emerald and amethyst, were cut to fit into channels and dance around designs. The newly-created and evenly-coloured synthetic sapphire and ruby calibré appear in late Edwardian pieces. Black enamel or onyx also provided contrast to the all white look as it transitioned from the mourning jewellery age.

A platinum and diamond central ornamentation could also be highlighted with a larger splash of colour from background bases of pastel toned, transparent to translucent enamels over an engraved gold base — a technique called ‘guilloche’.

Defining Traits of Edwardian Jewellery 

Further defining methods of this era are millegraining and fret work. Overall pieces are finished with delicate, minute beading making the metal disappear into the design. This millegraining took away the sharp edges, softening the look and emphasising the diamond sparkle. Millegraining also enhanced the knife-edged, open, thin wire work called fret work (like the frets for chords on a guitar neck) that created the airiness to the designs and highlighted the incredible expertise of the craftsman.

After WWI the flowing movement of the graceful Edwardian jewellery eventually blended into, and was then lost to, the geometrical, static, anticlassical, architectural style of the Art Deco era — that caught on like fire. Out with the old, and in with the new. 

Follow your passion for gemmology with one of our in-house diamond grading and gemstone workshops

This article was originally published in the Spring 2019 issue of Gems&Jewellery. Gem-A Members can read the issue online, here

Cover image: The front of a beautiful swan pin, showing the calibré cut emeralds and the typical swinging diamonds, all set in platinum. All images courtesy of Cole Bybee and Lang Antiques

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The History of Queen Victoria's Sapphire and Diamond Coronet

Queen Victoria (1819-1901) famously shared a love of fine jewels and coloured gemstones with her beloved husband, Prince Albert. In fact, one of her most prized possessions - a sapphire and diamond coronet - was designed and commissioned by her husband in 1840. Here, we delve into the story behind this beautiful piece of history.

It is perhaps fated that Queen Victoria’s sapphire and diamond coronet found its permanent home at London's Victoria & Albert Museum in 2019, not least because this year marks the 200th anniversary of the births of both Queen Victoria and Prince Albert. Now, housed within its own cylindrical display cabinet at the heart of the refurbished William and Judith Bollinger Gallery, Queen Victoria’s sapphire and diamond coronet is once again the star of the show. 

The coronet was first acquired by the museum in 2017 and is considered one of Queen Victoria’s most important jewels. It was lovingly designed by her husband, Prince Albert, in 1840 (the royal couple’s wedding year) and was made by jeweller Joseph Kitching.

The coronet is mounted with diamonds set in silver, with 11 step-cut sapphires of octagonal and calf’s head shape, set in gold. The piece was designed to match a sapphire and diamond brooch that Albert gave to Victoria the day before their wedding, perhaps kick-starting the Queen’s love of parures.

In fact, in the same year, she purchased a pair of diamond and sapphire earrings, a brooch and a bracelet of sapphires and diamonds, which suggests she was building a rather impressive matching set!

Read more: What Factors Influence Sapphire Prices?

The design of the coronet was based on the Saxon Rautenkranz – acknowledged as Prince Albert’s coat of arms – although the gemstones are believed to have come from jewellery previously given to Victoria by King William IV and Queen Adelaide.

Prince Albert took a keen interest in Victoria’s jewellery, with one of the Queen’s diary entries from February 1843 stating: “We were very busy looking over various pieces of old jewellery of mine, settling to have some reset, in order to add to my fine ‘parures’. Albert has such taste and arranges everything for me about my jewels.”

 

Queen Victoria, François Forster (1790-1872), Paris, 1846, after Franz Xaver Winterhalter (1805-73). Engraving on paper. © Victoria and Albert Museum, London.

Soon, the coronet was immortalised in influential early paintings of Victoria, including the 1842 official portrait by Franz Xaver Winterhalter, making the sparkling jewel a recognisable symbol of her power and status.

Prior to the untimely death of Prince Albert, Queen Victoria famously had a great love of colourful gemstones and transformable pieces that could be worn in multiple ways. In 1866, she wore the coronet in place of the heavy state crown at the first Opening of Parliament she attended after Albert’s death (perhaps signalling that the piece gave her confidence).

Speaking on the introduction of the coronet to the V&A, senior curator Richard Edgcumbe said: “Queen Victoria’s sapphire and diamond coronet is one of the great jewels of her reign. Designed by Prince Albert, it is an iconic symbol of their love, worn by Victoria as young queen and as widow. We are entirely indebted to William and Judith Bollinger and their sons for the gift of this masterpiece of the jeweller’s art, which is so intimately associated with Victoria and Albert that it will become part of the identity of the V&A.

"Together with an array of eighty new acquisitions and loans made possible by the generosity of many supporters, the display of the coronet inaugurates the next phase in the life of a much-loved gallery.”

All images credit to Jewellery, Rooms 91-93, The William and Judith Bollinger Gallery at the Victoria and Albert Museum (V&A).

This article was originally published in the Summer 2019 issue of Gems&Jewellery.

Thinking of enhancing your knowledge of diamonds? Take a look at our Diamond Diploma and Diamond Grading and Identification course.

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ロンドン塔の収蔵品「クラウン・ジュエル」

 

アンドリュー・フェローズ FGA DGAが、世界で最も有名な宝石コレクションである「クラウン・ジュエル」にまつわる神話や伝説を見ていきます.

有名なクラウン・ジュエルCrown Jewels が収められているロンドン塔の基礎は、征服王ウィリアムによって1066年に築かれました。そして、代々の君主たちによって改造や修復が重ねられ、13世紀後半までには今日見られる大体のレイアウトが確立しました。ヨーロッパで唯一現存するクラウン・ジュエルは141以上の宝物で構成され、何百年もの間ロンドン塔の中で安全に保存されてきました。これらは毎年、多くの観光客を惹きつけています

このコレクションには、単に宝物の美しさを堪能する価値があるだけでなく、宝石類の背後にある魅惑的な物語と歴史について学ぶ価値もあります。

帝国王冠(インペリアル・ステート・クラウン)

帝国王冠(インペリアル・ステート・クラウン)―コレクションにおける最も有名な王位の象徴― は、即位式終了後に君主が頭上に戴くもので、議会の開会の際にも使われます。王冠には、このような重要な行事に際して、王冠自体と同じくらい凝った専用の儀式用馬車が用意されています。王冠は実に3.17kgもの重量があり、短い間のみかぶることができます。

ジョージ4世が1821年に戴冠した際、王冠の重さが理由で歯痛になったという逸話があります!王冠にはロイヤル・コレクションにおいて重要な宝石がいくつか使われており、その多くには非常に面白い物語があります。

黒太子のルビー

多くのジェモロジストがよく知っている物語の一つとして、黒太子のルビーが挙げられます。これは、最も美しい宝石であると同時に最も不吉な石といわれています。そればかりか、完全に誤った名がつけられています。ルビーと呼ばれていますが、実際は非常に大きな宝石品質のレッド・スピネルです。この宝石は、デューク・オブ・コーンウォール、プリンス・オブ・アキテーヌと呼ばれ、「黒太子」とも称される14世紀のプリンス・オブ・ウェールズであったエドワード皇太子(エドワード・オブ・ウッドストック)に贈られました。

The Imperial State Crown. Copyright Cyril Davenport. Tower of London
帝国王冠(インペリアル・ステート・クラウン). Copyright Cyril Davenport

王冠の前部のカリナンIIより上にあるクロスパティー(末広十字)についているこのスピネルには、黒い、血の歴史があります。14世紀に書かれた最初の記録によると、ムーア人の皇太子であったアブー・サイードがこの石を所有し、ペドロ残酷王が征服していた軍隊に引き渡そうとしますが、彼は休戦旗の下で待ち伏せされ、奪われたこの大きなスピネルで処刑されました。これがまさに血の軌跡の始まりです。その後、ペドロは軍事援助のための頭金としてこの石をエドワード皇太子に差し出しました。支払いの残りは宝物と宝石から成ると思われていましたが、決して支払われることはありませんでした。そして、結局、ペドロは彼の異母兄弟に待ち伏せられて刺し殺されました。

後にこの石は、1415年のアジャンクールの戦いで、ヘンリー5世のヘルメット(兜)につけられ、言い伝えによると石が彼の命を救ったとされています。斧で彼の頭が強打されたときそのヘルメットは破壊されたものの、彼を死に至らしめることはありませんでした。「ルビー」は粉砕されたヘルメットから取り出され、ヘンリー5世が亡くなるまで手元に置かれました。残念なことに、リチャード3世に関しては同じことは起きませんでした。彼もまた1485年のボズワース・フィールドの戦いのとき、「ルビー」をヘルメットにつけていました。おそらく、彼は石が身を守ってくれる、運をもたらすと思っていました。しかし、悲しいことに、彼は戦場で死んでしまいます。この同じ「ルビー」は後にチャールズ1世によって売却されるまで、ヘンリー6世とエドワード4世の王冠、ヘンリー8世(彼は石をを襟に着けていた)に使われました。そしてこの石は王室に戻りチャールズ2世の王冠に用いられ、その後ジョージ4世の即位式で使われました

聖エドワードのサファイア

また、帝国王冠の上部の十字架には、サファイアがセットされています。伝説によれば、このサファイアは、かつて証聖王エドワード(信仰のあつい英国王)の即位の指輪(コロネーション・リング)につけられていました。ある夜、エドワードがウェストミンスター寺院の前を通ると、一人の乞食に遭遇しました。彼は持っていたすべてのお金をすでに寄付してしまっていたので、深く考えずにその乞食にサファイアのついた指輪を与えました。

数年後、2人のイングランド人が聖地巡礼中、嵐に襲われました。その時1人の老人が彼らに近づいてきました。そして、2人の男がイングランド人であること、エドワードが今も国王であることを聞き、その老人は彼らに嵐の避難所を提供しました。翌朝、彼らが出発する際、老人は、自分が福音記者ヨハネであることを明かし、数年前にエドワード国王が指輪をくれたことを話しました。老人は親切のお礼に6か月後に天国で会うでしょうというメッセージとともに指輪を国王に返してほしいと彼らに託しました。2人の男がイングランドに帰国すると、エドワード国王に指輪とメッセージを渡しました。そして、国王は直ちに自らの死に備えました。国王は6ヵ月後に亡くなり、指輪をはめて埋葬されました。不思議なことに、事実、墓が12世紀に再び開けられたとき、その指輪は完全に保存された遺体の上で見つかりました。

Tower of London at night. Copyright Kjetil Bjørnsrud. Tower of London
夜のロンドン塔. Copyright Kjetil Bjørnsrud

これらの物語の一部は単に伝説であって、本当かもしれませんし、そうではないかもしれません。しかし事実として、クラウン・ジュエルの中で最も有名で世界で一番大きなダイヤモンドは、コー・イ・ヌールとカリナンであると言えるでしょう。

カリナン・ダイヤモンド

カリナンは、1905年1月26日の午後に南アフリカのプレミア鉱山で、鉱山本部長であったキャプテン・フレデリック・ウェルズによって発見されました。それは3106ctの重さ、3 7/8×2 1/4×2 5/8インチで、その日までに発見された他のどのダイヤモンドよりも2倍以上の大きさであったため、当初、彼はこの石がダイヤモンドであることに疑いをもちました。その後、石はトランスバール政府に£150,000で売却されました。そして、2年後には未カットの状態でエドワード7世の66回目の誕生日に贈られました。その規模や価値はわからなかったものの、石のカットは、大きな石をカットする経験のあるアムステルダムのI. J.アッシャー・アンド・カンパニーに依頼され、3ヵ月検討した後、ようやくカリナンはカットされることになりました。

当時、ダイヤモンドを分割する唯一の方法は劈開を利用することでした。―ダイヤモンドの弱い方向に沿って割れるように正確な方向を「打つ」方法ですが、粉砕することを避けるために、慎重に行わなければなりませんでした。そして石を慎重に劈開させた結果、9個の大きな「かけら」と96個の破片になりました。全てのカット工程が終わった後に残った重量は合計1063ctでした。

カリナンⅠ~カリナンⅨと名付けられた9個の大きな石はすべて、ロイヤル・コレクションに属しています。大きい石は、他のジュエリーにも使用できるようにセッティングが作られます。別名「アフリカの星」と呼ばれるカリナンⅠは王笏に用いられ、503ct以上の重さがあります。この石は世界最大の無色のペア・シェイプ・ダイヤモンドです。カリナン II(「アフリカの小さい星」)は、世界最大のクッション・シェイプ・ダイヤモンドで、317ctの重さがあり、帝国王冠の正面にセットされています。この石にもセッティングには2つのプラチナの輪がついており、取り外しが可能です。そしてブローチやペンダントとして単独で着けられ、またカリナン Iと共に着用することもできます。

コー・イ・ヌール・ダイヤモンド

2番目に注目に値するダイヤモンドは、皇太后の王冠にあります。これはコー・イ・ヌールと呼ばれており、「光の山」という意味をもちます。この印象的なダイヤモンドの現在の重量は105.6ctで、もともと186ctあったこの石は、1852年にヴィクトリア女王のためにリカットされました。

この石は、身に着ける女性に幸運をもたらすという伝説があります。しかし、男性には不幸がふりかかります!1739年にペルシャのナーディル・シャーがムガルを征服しましたが、統治者がもつとされるこの珍しい伝説のダイヤモンドを見つけることができませんでした。宮廷の1人が彼にこの石の在り処を話すと、シャーは祝賀会を開き、永遠の友好のしるしとして征服された指導者たちとターバンを交換することを申し出ました。なぜなら、これがコー・イ・ヌールの隠されている場所であったからです。

ダイヤモンドはその後、数十年の間しばしば持ち主が変わりました。1850年までに、コー・イ・ヌールはイングランドへ伝わり、ヴィクトリア女王へわたり、そして現在に至ります。

クラウン・ジュエルは素晴らしいイギリスの歴史がある一方で、伝説に包まれた装飾品以上の存在です。ここには多くの物語と歴史があり、訪れる人々がそれを発見するのを待っています。宝石学的、歴史的な視点でこの宝物を鑑賞するのも良いですし、決して買うことができない宝石を見るのも感動的です。ロンドンで有意義な一日を過ごす方法として、クラウン・ジュエルはお勧めです■ 

この記事はGem-Aの機関誌Gems&Jewellery Sept/Oct 2016 / Volume 25 / No. 5 pp. 14-15から引用したものです。

表紙はカリナン・ダイヤモンドの原石から分割されたカット前の9つの石を大きいものから順に並べたもの。


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Hidden Treasures: Highlights of Gem-A's Gemstones and Minerals Collection

Hidden Treasures: Highlights of Gem-A's Gemstones and Minerals Collection

Gem-A Gemmology Tutor Pat Daly FGA DGA offers us a glimpse at some of the more unusual items in Gem-A's Gemstones and Minerals Collection.

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Tanzanite: The Contemporary December Birthstone

Tanzanite: The Contemporary December Birthstone

Are you looking for the perfect festive gift for a December baby? Gem-A tutor Lily Faber FGA DGA EG considers tanzanite – one of three birthstones for December – and shares how this relatively new gemstone compares to its purple and blue-hued rivals.

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Birthstone Guide: Turquoise For Those Born In December

Birthstone Guide: Turquoise For Those Born In December

Beautiful blue turquoise is one of three birthstones for the month of December (in addition to zircon and tanzanite). It is enriched with real cultural significance that can be traced back thousands of years. Here, we explore the blue shades of turquoise and explain what makes this gemstone so special...

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Understanding the Cat's Eye Effect in Gemstones

Understanding the Cat's Eye Effect in Gemstones

Chatoyancy is the gemmological name given to the curious optical effect in which a band of light is reflected in cabochon-cut gemstones, creating an appearance similar to light bouncing off a cat's eye. Gem-A's Collection Curator, Barbara Kolator FGA DGA explains chatoyancy and highlights some of the many gems in which it can occur.

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Jade and its Importance in China

Jade and its Importance in China

Jade has long been revered by gem lovers internationally, but nowhere more so than in China. But what is it that makes this gemstone so special? Gem-A's Assistant Gemmology Tutor Dr Juliette Hibou FGA gives us an overview of jade, how to identify it and its significance in Chinese culture.

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Highlights of Gem-A Conference 2019

Highlights of Gem-A Conference 2019

The Gem-A Conference is always the highlight of our gemmological calendar! If you didn’t manage to make it, we’ve put together a few of the highlights from this year’s event to fill you in on what you missed, and whet your appetite for Gem-A Conference 2020!

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The Famous Diamond Collection of Cardinal Mazarin (1602-1661)

Having successfully completed her Gemmology Diploma and Diamond Diploma, Charlotte Pittel FGA DGA shares an abridged version of her excellent project on Cardinal Jules Mazarin and his legendary love of diamonds.

The Mazarin diamonds were a collection of 18 diamonds left to Louis XIV and the French Crown Jewels by Cardinal Jules Mazarin. Discovering the story of this group of diamonds, the man who collected them and what happened to them is like an incredible work of fiction.

The Life of Cardinal Mazarin

Born Giulio Raimondo Mazzarino on July 14, 1602 to a minor Italian noble family, Mazarin was a man of many interests and talents. His early education was at Jesuit school in Rome before studying law in Madrid. On his return to Rome around 1622 he attended the University of Rome La Sapienza, and following a spiritual awakening he entered the pontifical army.

In 1628 he joined the diplomatic services for the Holy See and became involved in Italian politics whilst working alongside the Cardinals Sachetti and Barberini. His subtlety, patience and hard work were recognised and in 1630, during the war between France and Spain over Mantua, he was sent to negotiate with Cardinal Richelieu.

A bust of Cardinal Jules Mazarin in Paris. Photograph by PlanetKorriban on Flickr (Creative Commons).

Richelieu, impressed with the young man, invited him to Paris where he soon became a confidant and advisor to the Cardinal, joining the court of Louis XIII and Queen Anne d’Autriche. After taking French citizenship he became known as Jules Mazarin and in 1641, was promoted to the rank of Cardinal.

Following Richelieu’s death in 1642, Mazarin succeeded him as the Chief Minister of France and, after the death of Louis XIII in 1643, assisted the Regent Queen Anne in governing France on behalf of her then child son, Louis XIV.

Mazarin was a keen student of the arts, but diamonds were his first love. His collection contained the most beautiful examples, many of them sourced from other European royal families, his preferred jewellers of the time including Lescot, Gabouri, Lopés, and almost certainly from renowned traveller Jean Baptiste Tavernier (1605-1689), who would also supply King Louis XIV.

The 18 Mazarin Diamonds. Illustration inspired by the work of author, Bernard Morel. Image: Charlotte Pittel.

Following his death, Mazarin made generous donations to hospitals, hostels and the arts, and bequeathed his extensive collections of jewellery and gems. Queen Anne received the Rose d’Angleterre (a large round diamond of approximately 14 carats) and a perfect cabochon ruby in a ring.

The Duc d’Orléans received 31 emeralds, while Queen Marie-Thérese was bequeathed a cluster of diamonds. Among his more noteworthy instructions, however, was his wish that a collection of 18 diamonds be given to the King and the Crown of France, on condition that they carry the name Mazarin.

The Famous Mazarin Diamonds

Mazarin assembled this rare and beautiful collection of 18 stones towards the end of his life. Only three of these stones are named: the Sancy, the Mirror of Portugal and the Grand Mazarin. Sadly, due to the tumultuous nature of 18th century French history, many of the 18 stones have disappeared.

An impression of the Mirror of Great Britain, as seen affixed to King James I's hat in a portrait that is housed in the Scottish National Portrait Gallery. Image: Charlotte Pittel.

The Mazarin I — the Sancy Diamond

It is believed that the 106 (old) carat Sancy formed part of the collection of Charles the Bold, Duke of Burgundy. Following his death it disappeared for over 20 years, finally reappearing in Germany in the hands of a merchant banker named Jacob Fugger. He planned to sell the diamond to the King of Portugal, Don Manuel I, and re-cut it into the pear shape we see today.

During a period of huge political upheaval and conflict between England, France, Spain and Portugal, the diamond would finally end up in the collection (and take the name) of Nicholas de Harley, Seigneur de Sancy and Baron de Maule (1546-1629).

De Sancy was made Superintendent of France by Henry IV and pledged his diamonds to raise money for the crown. In 1596, however, he negotiated the sale of the stone to James I of England, who set the Sancy as a pendant into the jewel known as the Mirror of Great Britain.

Read more: Diamond for Those Born in April

James’s successor Charles I sold off precious stones to raise funds for the Royalist cause and, in 1644, sent his consort Queen Henrietta Maria to France to secure supplies and munitions. She borrowed enormous sums from the Duke of Epernon and pledged the Sancy as collateral. In 1649, when Charles I was beheaded, the Queen was exiled. The Sancy diamond was claimed by the Duke and subsequently sold to Cardinal Mazarin.

The Sancy then became part of the French Crown jewels and was mounted in Louis XV’s coronation crown in 1722. Today, the Sancy is on display at the Louvre Museum in Paris.

John de Critz's 1604 portrait of James I shows the King wearing the legendary 'Mirror of Great Britain' jewel. Image: Public Domain.

The Mazarin II Diamond

Author Bernard Morel suggests that this stone could well be the Pinder diamond, based on a 17th century description and drawings made by Thomas Cletscher. Sir Paul Pinder was a businessman and diplomat and, in 1611, James I made him an ambassador to Turkey where he managed to acquire some exceptional jewels, including the Pindar.

Called at this time the Great Diamond, it was acquired by Charles I in 1625 for 18,000 livres but not paid for. It is likely that this is one of the stones pledged by Queen Henrietta Maria in 1646 and then acquired by Mazarin, becoming known as the Second Mazarin.

It was included in a diamond chain worn by Louis XIV, before being re-cut and set into the centre of the Order of the Golden Fleece made by Jacquemin for Louis XV. Thereafter it was unset and remained in the collection of Louis XVIII until his death in 1824, at which time it was returned to the Crown collection. Sadly, the stone was stolen during the 1848 revolution.

The Mazarin III — the Mirror of Portugal Diamond

This stone belonged to Dom Antonio, Prior of Crato. After a short period with Elizabeth I and named the Portugal Diamond, it was mounted into a pendant set with a large pearl drop and given to Henrietta Maria on her betrothal to Charles I. It eventually became a part of the Mazarin Collection.

Read more: Questions to Ask When Buying a Piece of Gemstone Jewellery

As was the custom, many of the French crown jewels were in settings that allowed a freedom in how they could be worn. As such, the Mirror of Portugal was set not only in Louis XIV’s diamond chain, but also in a hairpin worn by Queen Marie-Thérèse, which also bore the Grand Mazarin and some substantial pearls.

The Third Mazarin was unfortunately lost to the French Crown jewels when a substantial number of the jewels were sent to Constantinople never to return, including the Mirror of Portugal and many other Mazarins.

The Mazarin IV Diamond

This stone was first referenced in Bernard Morel’s book as being set into a pair of Girandole earrings created for Queen Marie-Thérèse. It is shown sitting as the top button with the Mazarin V as a drop. Its pair uses other diamonds, including the Mazarin VI as the drop.

An illustration of Queen Marie-Thérèse's girandole earrings, inspired by the work of Bernard Morel, containing some of the Mazarin diamonds. These earrings were documented in the 1691 inventory of the French Crown Jewels and were valued at 500,000 livres. Image: Charlotte Pittel.

The Mazarin V and VI Diamonds

Both the Mazarin V and Mazarin VI were pierced at the top, so were perfectly shaped to be worn as drop earrings. Records suggest that both of these stones were cut by Francisco Ghiot of Antwerp: 1632 for Mazarin VI and Mazarin V in 1636. In a later inventory of 1774, they show up possibly as rings.

The Mazarin VII — Le Grand Mazarin Diamond

This legendary coloured diamond was sold at Christies on the November 14, 2017, achieving a price of CHF 14,375,000 (approximately GBP £10,969,567.60). A GIA certificate (No. 5182785154) and classification letter confirms that this historic light pink, old-mine brilliant-cut diamond is a Type IIa and weighs approximately 19.07ct.

Read more: The Geology of Diamonds

This diamond can be traced back to Indian mines near the Golconda trading centre, but quite how it came to Cardinal Mazarin is unknown. Once the diamonds were passed to Louis XIV and the Crown Jewels collection, it is believed that Queen Marie-Thérèse was the first to wear it.

Following her death in 1683, Louis regained the Grand Mazarin and added it to his legendary chain of diamonds. It was listed in the 1691 inventory as sitting at number five on a chain of 45 diamonds, numbered in descending order of size. It was added to the crown of Louis XV, along with the Sancy.

The Mazarin VIII Diamond

One of the few diamonds to survive a significant sale in 1795, this Mazarin stone sat at either position six or seven on Louis XIV’s diamond chain. The standout piece in which it featured, along with the Grand Mazarin, was the Diamond Diadem of Marie-Louise, Empress of the French from 1810 to 1814. A large diamond parure was ordered soon after the wedding of the Emperor and Empress, along with a coronet, a necklace, pair of bracelets, girandole earrings and a belt. There was also an order for a substantial diadem.

An impression of Empress Eugénie's reliquary brooch designed and created by Alfred and Frederic Bapst in 1855. It was sold to the Louvre Museum in Paris in 1887. Image: Charlotte Pittel.

The Mazarin IX Diamond

Originally described as boat-shaped, the term ‘marquise’ was coined during the reign of Louis XV, largely due to a rumour that it matched the lip shape of his mistress, Madame Marquise de Pompadour. This diamond was set as the eighth button on one of Louis XIV’s justacorps (an open-fitted coat).

The Mazarin X — XVI Diamonds

Along with others, these diamonds were also included in the diamond chain belonging to Louis XIV and also in the coronation crown of Louis XV. The Mazarin XII was described as having a red colouration, probably due to the reddish flaw in its girdle.

The Mazarin XVII-XVIII Diamonds

The last two stones of the collection - XVII and XVIII - were virtually identical, with XVIII slightly larger. It seems that these stones were kept as a pair and used as buttons on a coat belonging to Louis XIV. They are most famed for being part of Empress Eugénie's reliquary brooch of 1855, now part of the collection at the Louvre.

The Mazarin Cut

It should be noted that none of the 18 diamonds that Cardinal Mazarin bequeathed to Louis XIV were cut in the ‘Mazarin cut’. Instead, the cuts were as follows:

  1. Pear-shape double rose cuts — I (Sancy), V and VI
  2. Rectangular table cuts — II (Mirror of Portugal), III, IV
  3. Square table cuts — VII (Grand Mazarin), VIII, X, XI, XII, XIII, XV, XVI
  4. Heart-shape flat rose cuts — XVII, XVIII
  5. Marquise — IX

The fashioning of diamonds in 17th century Europe was undeveloped. Until the 1400s the natural form of the diamond was used, so an octahedral crystal or other rough was refined and set (known as the ‘point cut’). The table cut was first seen around 1477, marking the first true cut where the octahedron crystal had its top flattened by grinding and sometimes a culet added to the lower point. Varieties of the table cut are the thick table cut, the mirror cut, the tablet and the lasque cut.

A representation of the Mazarin Cut, inspired by the drawings and insights of Eric Bruton and Herbert Tillander. Image: Charlotte Pittel.

After the table cut followed rose-cut stones; a flat backed stone with a domed front. There were a variety of rose-cut styles in use at the beginning of the 15th century and it was considered the most appropriate cut for a flatter, thinner stone. Early brilliant cuts were first seen in the mid- 1600s, leading us back to the diamond-loving Cardinal Mazarin.

Single-cut or eight-cut diamonds had eight facets on the table and eight facets on the pavilion plus a culet. These then evolved into the double, cut with 16 facets on the table and 16 facets on the pavilion plus a culet.

It was in the mid-17th century that the Mazarin cut appeared, cushion-shaped with 34 facets in total: 17 facets on the table and 17 facets on the pavilion, including the culet, plus a girdle. This design of facets greatly increased the diamond’s reflective properties and it showed more fire and brilliance.

Although Mazarin was a devoted diamond collector, it is unlikely that he actually invented the Mazarin cut. However, he was a definite forerunner in the rise of popularity for this style of cutting and it is most likely that the cut was named after him as a tribute.

The complete version of this project, including references, appendices and a bibliography are available upon request. All images and illustrations are supplied by the author unless otherwise stated.

This article was originally published in the Spring 2019 issue of Gems&Jewellery.

Do you share Mazarin's passion for diamonds? Enhance your knowledge with our Diamond Diploma.

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サバイバーズ ― ダイヤモンドの地質学

 

これはGem-Aの機関誌「Gems&Jewellery」2018年春号より引用した記事です。Gem-Aのアシスタント・チューター、ベス・ウェスト FGA DGAがダイヤモンドの壮大な旅をたどり、ダイヤモンド特有の強さについてその起源を古代から探ります。

「彼らが棲んでいた深い谷間では、すべてのものが人間より古い存在であり、それらは神秘の歌を静かに口ずさんでいたのだった」
コーマック・マッカーシー著『ザ・ロード』

炭素は宇宙で4番目に豊富な元素であり、生命にとって最も重要なものの一つです。私たちはおよそ18%の炭素で成り立っています。しかしダイヤモンドの場合は、純粋な炭素で形成され、天然に存在する地球上で最も硬い物質となる方法で結合しています。

しかし、この素晴らしい宝石からは、美しさと耐久性のはるか彼方にある、私たちの世界の始まりをささやく声が聞こえます。

ダイヤモンドは何歳?

最も古いダイヤモンドはおよそ35億年前の太古代に形成されたと証明されています。この時点では、惑星はおよそ10億年間のみ存在していたと考えられていました。そして、地表の状態は安定していました。

ダイヤモンドはどのように生成されるか?

地球はいくつかの層から成ります。最も外側の層は地殻と呼ばれ、6km~40kmの深さがあります。そしてさらに大陸で構成される厚い大陸地殻と海洋地殻 ―つまり海底― に分けられます。地殻の下にはマントルがあり、地球全体の10分の8を占め、主に橄欖岩(かんらんがん)という火成岩で構成されています。

マントルの最上部と地殻はリソスフィア(ギリシャ語で「岩石が多い領域」の意味、岩石圏ともいう)と呼ばれます。この部分は堅いものの、マントルの深い部分では岩石が熔融したり冷えたりして、永久に対流の状態にあります。地球の中心では、液体の外核が固体の内核 ―5500°Cの鉄とニッケルでなる中心部― を覆っています。

太古代に地殻は動いて分裂し、その切り離された部分はそれぞれの場所に落ちつきました。古い動かない地殻の部分を「クラトン」と呼びます。それぞれのクラトンの下、最大300キロメートルの深さにリソスフィア・マントル・キールがあります。このキールは深い部分でもおよそ1200°Cであり、対流によって熱を循環させているマントルよりも温度の低い場所です。

およそ40000気圧に相当する圧力があれば、ダイヤモンドの生成が始まります。これは、およそ140kmの深さと同じです。クラトンの下の深いリソスフィア・キールは、対流によって熱を循環している混沌としたマントルから離れているため、ダイヤモンドが成長するのに最適な場所となりました。

ペトラ・ダイヤモンド社の南アフリカ、フィンシュ(Finsch)鉱山。露天掘りとその後に行われるブロック・ケイビング法(トンネルが見える)。
写真: Charles Evans FGA DGA.

炭素はどこから来たのか?

炭素は、原始時代の(地球の出生から存在した)物質から生じた、または海底が大陸地殻に衝突して押し下げられた時にマントルに引き込まれた物質から生じたと考えられています。

炭素は、マントル付近の流体の中でメタン(CH₄)や炭酸塩(CO₃)等の化合物に閉じ込められています。この流体がマントル・キールを通過すると、橄欖(かんらん)岩に反応し、炭素は化合物から離れてダイヤモンドとして結晶します。最も古いダイヤモンドが生成されたのは、キールの深部です。

ダイヤモンドはどのようにして私たちに届いたのか?

ダイヤモンドは、マントルの深部で生じるマグマの力強く激しい噴火によって深部から噴出されるまで、何千万年もの間、恐竜時代(およそ3億年~8000万年前)頃までキールに留まっていました。

3種類のマグマの中でキンバーライトが最も豊富にダイヤモンドを含んでいます。この強力なマグマが噴火によって「パイプ」と呼ばれる円錐形の穴をつくり、地表まで到達します。噴火で上部に運ばれたダイヤモンドは、穴に閉じ込められたマグマの砕屑物の中にとどまるか、あるいは地表で風化され ―何百万年の間、川や氷河の中で長距離を旅します。

地球の深部から私たちが身に着ける指輪までの道のりをたどると、ダイヤモンドの強さがはっきりとわかります。私たちがダイヤモンドの輝きに包まれるとき、この驚くべき旅を思い出してみてください。

この記事はGems&Jewellery Spring 2018/ Volume 27/ No.1  より引用したものです。

表紙:ダイヤモンドの結晶。写真: Pat Daly

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アンティークのエドワーディアン・ジュエリーの見分け方

 

歴史家、査定人、アンティーク・コレクターにとって、様々な時代やデザインの流行からジュエリーを見分けることは必要不可欠です。ステラ・ターナー FGA GGが、上品で洗練されたエドワーディアン・ジュエリーの世界を紹介し、この時代に特徴的なモチーフについて解説します。  

短かったエドワード7世の治世(1901~1910年)、宮廷ではエドワード王が好んだスポーツを中心としたライフスタイルとデンマーク出身のアレクサンドラ王妃の存在が、1800年代の終わりの流行に新しい風を吹き込みました。それに伴ってジュエリーのモチーフは変化を遂げました。ダイヤモンドを散りばめ、複雑、優雅で均整の取れたレースのようなデザインが流行し、ネックラインや、裕福なシフォンのガウンと「結い上げた」ヘアー・スタイルを飾るようになりました。繊細なスクロール、葉、リボン、ハート、サークル、揺れる垂れ飾り(あるいは、後述するガーランド)、そしてベールのように軽やかなジュエリーは、洗練された新しいスタイルを称えるものでした。

私にとって、エドワード時代のデザインは「凍った瞬間」のように見えます-渦巻き状の動き、かすかな輝き、ゆるやかなドレープ、スクロール、そして揺れ動き、円を描く-それは、ジュエリーが身に着けられ、再び動く時を待つかのようです。エドワード時代の女性らしさ、流動性、繊細さがデザインによく表れています。この時代のジュエリーは基本的に、蝶番、垂れ飾り、花綱、動きを出す構造、流動性、小さく揺れ動く宝石でできた滴で構成されています。

アレクサンドラ王妃は、着け心地はいまいちでありながらも、ファッション性に富み、装飾を施したプラーク(板)のついた「ドッグ・カラー」ネックレスを好み、黒いベルベットを付けて愛用しました。そして、このスタイルは後に6-16列に並べた真珠へと形を変えました-身に着けるのが難しいものです。ドレスのネックラインが変わると、首周りの装飾品にも変化をもたらしました。例として挙げられるのは、リヴィエール・ネックレス-ミルグレイン(ミル打ち)で縁取られた覆輪留めのダイヤモンドが一周したグラデーションの付いた連-であり、これは二本のブレスレットとして着用されることもあります。

ダイヤモンドに「スペクタクル・セット」を施した最長72インチの長い連のネックレスもあります。これは細いワイヤーでダイヤモンドのガードル部分を巻き、脇についた小さな丸カンを隣の宝石につなぐというシンプルな技法です。またラヴァリエールは、デザインが同じパーツから滴状の飾りが下がるように、装飾を施した細い鎖で繋いだネックレスです。ネグリジェ・ネックレスは、二つの飾りが時折異なる長さのシンプルなチェーンで一つのデザイン・パーツからぶら下がったものです。通常、ペンダント(ぶら下がる部分)には、ダイヤモンドがセットされ、彫刻や次第に先が細くなった飾りがあり、繊細にデザインされたチェーンで繋がれています。

ティアラもまたエドワード時代の興味深いジュエリーです。ティアラに似たバンドーはネックレスやブレスレットにも使用することができます-後部にあるネジ穴またはループは、形を変えることができる融通性を示しています。長い真珠の連を束ね、先端にタッセル(飾り房)の付いたソートワールは、首、腰、ボディス(肩からウエストまで)、腕に巻き付けて装いました。ブレスレットには、一周、または上部半周を対称的に繰り返すデザインが用いられました。新しい流行は、先が細くなるデザインをつけた小さなダイヤモンドや色石のブレスレットで、後ろ側で連結金具を繋いだものでした。リングは中央のダイヤモンドの深さが十分に収まるように幅が広くドーム状になりました。

Edwardian Swan Brooch Back by Lang Antiques Gem A Blog Antique Jewellery Vintage美しい白鳥のピンの裏側。エドワード時代に典型的なカリブレ・カットのエメラルドと「スウィングする」ダイヤモンド。

堅いプラチナまたはプラチナを付けたゴールドは、淡くやわらかい女性らしいファッションの色調によく合いました。プラチナは新しい白い金属で、シルバーとは異なり、肌や衣服を汚すことなく、強度があり、最も重要なダイヤモンドを繊細に留めることができました。当初、プラチナはイエロー・ゴールドに接着されました。この技術は新しく、高価でない、価値が認められていない金属に付加価値をもたらしました。

私が見てきたエドワード時代のダイヤモンド・ジュエリーの大多数は、手作り(カット、切断、引き延ばし、引き絞り、組み立て)の作品です。金属を溶かすのには高温を必要とするため、キャストで作ったものは一般的ではありません。イエロー・ゴールドをベースとしたロウを使用しているのが見えてしまうので、エドワーディアン・ジュエリーは通常少ないパーツで組み立てられています。

金属の継ぎ目に見られる黄色味を帯びたロウは、ホワイト・ゴールドが作られるようになった第二次世界大戦後には、白色に近くなり、姿を消しました。さらに、プラチナは素晴らしい金属で-変色しません-変色が見られる場合には、ゴールド、シルバー、プラチナを混合したロウが用いられています。変色や錆は年月が経つにつれて生じるため、そのジュエリーが古いものであることがわかります。金属の磨きなおしは、時に古いものである証拠を取り除いてしまうことがあります。

当時、南アフリカは大量のダイヤモンドを供給していました。第二次ボーア戦争(1899年10月-1902年5月)はダイヤモンドの価格に影響を及ぼしましたが、需要は伸び続けました。この頃になると、ダイヤモンド用の丸い鋸、正確な角度をつけるための固定したドップ(カットするダイヤモンドを保持する締め金)、ブルーティング用の機械の向上と電気によって、カッティングに要する時間を削減しました。これはまた、より輝くラウンド・ヨーロピアン・カットのダイヤモンドを生むことにもなり、マーキーズやペア・シェイプも入手しやすくなりました。そして、カットの際には重量の保持よりも仕上げたダイヤモンドの美しさに焦点を当てるようになりました。

Edwardian Brooch by Lang Antiques Gem A Blog Antique Jewellery Vintageティアラにもヘア・オーナメントにもなるエドワード時代のピン。

後の時代にはシングル・カットのダイヤモンドが過去のローズ・カットに取って代わります。ダイヤモンドを早くカットできるようになり、煌めく17面をもつシングル・カットは、繊細なジュエリーを上手く引き立てることとなりました。小さなスイス・カットとヨーロピアン・カットのダイヤモンドは時代を見分けるのにも役立ちます。エドワード時代の終わりには、オールド・マイン・カットは無くなりましたが、このカットのダイヤモンドは、今もなお新しいジュエリーに再利用されています。

真珠はダイヤモンドに次ぎ二番目に人気があり、エドワード時代のモノクロのスタイルに合っていました。真珠の優美な光沢は、薄手のファブリックと組み合わせると美しく映えました。ぶら下がった滴状の飾りは、まるで水のようにオープン・ワークのデザインに素晴らしい動きの要素を加えました。天然真珠(この時まさに、養殖真珠はかなりの数が市場に登場するところでした)は稀少であったため、3.5mmのシード・パールまたはそれより小さいものは半分で使えるようにカットされ、金属にセットされました。

インド洋やペルシャ湾の海水産真珠はクリーム色~明るいグレー(洗浄に使用する洗剤でグレーになることがあります)で滑らかな表面であるのに対し、アメリカとスコットランドの淡水真珠は白くしわが寄っています。カットしていない大きい天然真珠は、時にボタン型やオーバル型の形状をしています。真円養殖真珠がエドワーディアン・ジュエリーに見られる場合、この真珠は既に取り換えられたものの可能性があります。サファイア、エメラルド、オパール、ルビー、アメシスト、デマントイド・ガーネット、ムーンストーン、ペリドットといった宝石は、周囲を複数のダイヤモンドで飾ったリングに仕立てます-これは、ヘイロー・リングと呼ばれるものです!カシミール産サファイア、ビルマ産ルビー、ロシア産デマントイド・ガーネット、オーストラリア産ブラック・オパールなど、古いジュエリーから宝物を見つけてみましょう。

Edwardian Oval Diamond Brooch by Lang Antiques Gem A Blog Antique Jewellery Vintageエドワード時代の透かし細工のブローチ

とても小さく(1-2mm)真っ直ぐな面をもつ幾何学的な形状のルビー、サファイア、エメラルド、アメシストは、チャンネル・セッティングに合うようにカットされたもので、このカリブレ・カット石はデザインに沿ってセットしていきます。新しく作られた均一な色の合成サファイアやルビーのカリブレ石はエドワード時代後期のジュエリーに見られます。ブラック・エナメルまたはオニキスは、モーニング(喪)・ジュエリーの時代が終わりを迎え、真っ白な見た目にコントラストを与えるものとして使用されました。

プラチナとダイヤモンドでできた中央の装飾は、淡い色の背景によって強調されます。この背景は彫刻したゴールドの土台に透明から半透明のエナメルを施したもので、「ギヨシェ」という技法です。

他にもこの時代の技法にはミルグレインと透かし細工があります。ジュエリー全体が繊細に仕上がり、微小なビーディング加工により金属がデザインに溶け込みます。このミルグレインは鋭い縁を取り除き、滑らかな見た目を作り、ダイヤモンドのきらめきを強調する効果があります。またミルグレインは、透かし細工(ギター・ネックの弦の格子模様のような)と呼ばれるナイフ・エッジのオープン・ワイヤー・ワークをも引き立てます。この細工はデザインに軽やかさを生み、職人の驚くべき専門的技術が際立つものです。

第二次世界大戦後、上品なエドワーディアン・ジュエリーの流行は、最終的にアール・デコの幾何学的、静的、反古典的、建築的スタイルに融合して消えていきました- このアール・デコ・スタイルは瞬く間に人気を博しました。古いものを捨て、新しいものを取り込んだのです。  

Gem-Aのダイヤモンド・グレーディングと宝石のワークショップに興味がある方は、こちらをご覧ください。

この記事は「Gems&Jewellery」Spring 2019号に掲載されたものです。Gem-A会員の方はこちらのオンラインからもご覧いただけます

表紙の写真:美しい白鳥のピン(正面)。プラチナにセットされたカリブレ・カットのダイヤモンドと「スウィングする」ダイヤモンド。写真提供:Cole Bybee and Lang Antiques。

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