The Science of Gem cutting combines traditional gemmological knowledge with an advanced understanding of optics to help you understand WHY different cuts help or hurt the colour and brightness of a stone as well as WHAT each of the traditional cutting styles does for light and dark toned stones.
This workshop will tackle the fuzzy intersection where gem cutting and gemmology overlap, looking thoroughly at design aesthetics, as well as an extensive exploration of colour and how the cutter can manipulate and master it through cut design.
This workshop is for anyone in the gem and gem cutting trade who wants to dive deeper into the physical world of gem cutting. It’s ideal for anyone who wants to understand how science comes into play during the gem cutting process and wants a better understanding of what to look for when buying cut stones and what to ask for when commissioning a lapidary to cut or recut a stone for maximum beauty.
Limited places available
Speaker: Justin K Prim FGA
Justin K Prim is an American gem cutter and author. He has been cutting gemstones since 2013 and has trained as a lapidary in the United States, Sri Lanka, France, the UK, Thailand, and Switzerland.
To support his work as a gem cutter, he has attended gemmology programs at GIA and AIGS. Justin previously taught faceting at the Institute of Gem Trading in Bangkok as well as teaching gemmology courses at AIGS Bangkok before founding his own gem cutting school, Faceting Apprentice Institute.
He has published two books on gem cutting which collect the world’s classic and historical faceting patterns and presents them in an easy to cut format with gemmological information.
Aside from teaching and writing, Justin also gives talks and presentations about faceting and faceting history around the world.
Main image (c) Justin-K-Primm (https://medium.com/justin-k-prim/i-dream-of-being-a-gemcutter-ba0fa492be78)
The Gem-A office will be closed from 3pm Wednesday 24th December 2025 for the holidays, reopening 9am Friday 2nd January 2026.
Season’s greetings from all of us at Gem-A!