Jeffery Bergman is an American born precious gemstone dealer and gemmologist with over five decades of broad-based experience in fine natural gemstones, natural diamonds, fine jewelry, mineral specimens, fossils, meteorites, and gemstone objets d’art. Co-Founder and Director of EighthDimensionGems.com (Formerly Primagem)  in Bangkok, Thailand, Jeffery cut & polished his first gemstone at the age of fourteen starting him on a lifelong career which has taken him to more than 70 countries, and every continent except Antarctica.

Jeffery’s formal gemmological training was accomplished at SSEF, the prestigious Swiss Gemmological Institute in Basel, Switzerland where he successfully completed his Basic, Diamonds, Advanced Pearls, Advanced Colored Stones & Scientific Gemmology courses qualifying him as an SSEF SGC. SSEF’s President Martin Häuselmann and Director Dr. Michael S. Krzemnicki declared Jeffery to be a “profound expert in gems”. Additionally, he is a Senior Accredited Gemologist member of the Accredited Gemologists Association, Honorary Professor for the Asian Institute of Gemological Sciences, and Vice President, Emeritus of the International Gem Society, an online gemological educational website with over 10,000 paid subscriptions.

As well as his gemstone and jewelry expertise, Jeffery has been collecting mineral specimens fossils, meteorites, gemstone objets d’art, and reference gemstones including types, origins, enhancements, synthetics, and imitations since he was fourteen years old. Over the five decades of his career, he has made numerous specimen donations to museums including The Milan Natural History Museum, The American Museum of Natural History, The Natural History Museum of Los Angeles County, The Smithsonian National Museum of Natural History, The Harvard University Mineralogical & Geological Museum, The Alfie Norville Gem & Mineral Museum – University of Arizona, and over 400 items to The University of Arizona’s Gem Science Department.

Jeffery’s gemstone cutting experienced has contributed greatly to his expertise as a colored gemstone and diamond supplier. Working one-on-one with some of the most technically advanced cutting factories in Asia insures he is able to supply finished products meeting the very highest of international standards. While based in Thailand, demand for his expertise regularly takes him to the trading centers of the world visiting clients in Paris, Geneva, London, New York, Hong Kong, Shanghai and Yangon.

While certainly not his major focus, appraising fine jewelry, gemstones, fossils, meteorites, mineral specimens, and gemstone objets d’art for manufacturing jewelers, dealers, private collectors, and as an expert witness in court proceedings has been an important adjunct to Jeffery’s primary business activities. He has been privileged to appraise a Guinness World Record holding Burmese sapphire, the world’s finest collection of round uber-rare non-nacreous wild natural pearls, and other highlights including exceptional bespoke high jewelry items for haute joailleries, and a wide variety of items for high-end gemstone and jewelry dealers.

Featured in many gem and jewelry periodicals, Jeffery has also appeared in interviews on the ABC, BBC, CCTV, CNA, CNN, NBC and GEO. He has been quoted in Time, USA Today, National Geographic, Discover, GIA’s Gems & Gemology, Gem-A’s Journal of Gemmology, ICA’s InColor and many other publications around the world. Jeffery is a frequent guest speaker at GIA Gem Gatherings, gemological conferences & universities, a regular contributor to gemological and other publications.

Basic Gemmology Course Diploma (SSEF BGC) – July 2014
Basic Diamond Course Diploma (SSEF BDC) – October 2017
Advanced Training Course Coloured Stones Certificate (SSEF ATC Coloured Stones) – April 2016
Advanced Training Course Pearls Certificate (SSEF ATC Pearls) – May 2017
Scientific Gemmology Course Certificate (SSEF SGC) – June 2015
GIA Colored Stone Treatment Update – May 2014
GIA Identifying Diamond Treatment – May 2014

AGA, TGJTA

Honorary Professor for the AIGS – Asian Institute of Gemological Sciences

Vice President Emeritus of the IGS – International Gem Society

2009 GIA Gem Gathering Bangkok – Meteorites: Heavenly Jewels
2009 GIA Gem Gathering Bangkok – Trapiche: The Rising Star
2010 GIA Gem Gathering Bangkok – Opal: Still the Queen of Gems
2011 GIA Gem Gathering Bangkok – Spinel: The Great Impostor
2011 GIA Alumni Assn. Atlanta, Georgia – Spinel: The Great Impostor
2012 World of Gems Conference III Chicago – Hexagonal geometry in art, architecture, religion, biology, minerals,
gemstones and jewelry
2012 GIA Gem Gathering Bangkok – A Dazzling Evolution: Co-evolution of life and minerals generating diversity
and complexity in gemstones
2012 GIA Alumni Assn. San Francisco – Spinels & Opals
2013 GIA Gem Gathering Bangkok – Tanzanite: Facts, Fairytales and Fakes
2013 JCK AGTA Las Vegas – Tanzanite rumors in the industry
2013 Italian Gemmological Conference, Naples – Tanzanite: Facts, Fears & Fairytales
2014 GIA Gem Gathering Bangkok – Geometric Passion & Obsession: How Hexagons Shape Gems and
Jewellery
2014 GIA Alumni Assn. San Francisco – Tanzanite: Facts, Fears & Fairytales
2015 AGA Tucson Conference. Collector Gems: A Co-Evolution of Life, Minerals, and Technology
2015 GIA Gem Gathering Bangkok – Opal Treatments: Facts, Fears & Fairytales
2016 Mediterranean Gemmological & Jewellery Conference, Valencia, Spain – Phenomenal Prices – Market Value
of Phenomenal Gems
2018 NAJA Tucson – Shakiso Ethiopian Emeralds
2018 First Iranian Gemological Symposium, Kish, Iran – Shakiso Ethiopian Emeralds
2018 GIA Alumni Assn. Houston – Mineral Diversity & Complexity – CoEvolution of Life & Minerals
2019 AGA Tucson Conference – Our Newest Emerald Source (Ethiopia)
2019 AIGS Seminar Hangzhou, China – Rubies, Sapphires, and Emeralds
2019 AGS Arizona Guild Meeting – Hexagons: From Passion to Obsession
2021 IIG – International Institute of Gemology, Bengaluru, India – Kashmir Trapiche Ruby from the Batakundi mine
2022 6th Mediterranean Gem and Jewellery Conference in Thessaloniki, Greece – Spinel: History, Origins,
Treatments, Marketing and Pricing
TRADE ALERTS:
1997 GEMS & GEMOLOGY Fall pg. 221-222 – Lab Alert: Radioactive cat’s-eye chrysoberyls
1997 Asia Precious, 5. 12. Pg. 18-19 – Radioactive cat’s-eye warning
1998 Professional Jeweler – RADIOACTIVE GEM ALERT!
2000 November Asiaweek – Feeling the burn from hot rocks: A radiation scare hits the gem business
2007 JCK MAGAZINE July 20 – Alert: Topaz with Unstable Color
2015 OpalholicsAnonymous.com – Trade Alert on Zultanite
2016 CIBJO GEMMOLOGICAL COMMISSION pg. 82 – Radioactive cat’s-eye warning
2017 Journal of Gemmology 35 / 7 / pg. 571 – Color-Change Glass Sold As Natural Garnet Rough
RESEARCH AND CONTRIBUTIONS:
2022 Spring Gems & Gemology, pg. 63 – Apatite Oiling: Before and After
2021 Emerald: Modern Gemmology by Dietmar Schwarz & Martial Curti pg. 03
2021 # 12 – A lesson from Jeffery Bergman, a master gemologist and a world respected gem dealer who started
from the bottom by licking opals.
2020 Spring Gems & Gemology, pg. 170-171 – Trapiche Gems
2019 Spring Gems & Gemology, pg. 85, 150 – Ethiopian Emerald
2019 May, GIA.edu Emerald: The Superstar of Trapiche Gemstones
2018 ICA InColor Special Emerald Issue – The Ethiopian Halo-Shakiso Emerald pg. 68-72 plus cover photo
2017 Ruby & Sapphire: A Gemologist’s Guide pg. Cover photo, pg. 191,192, 334
2017 National Jeweler – 5 Things to Know About … Trapiche Gems
2017 Ruby & Sapphire – A Gemologists’s Guide Cover photo, pg. 93, 104-105, 230, 295, 312, 350, 525, 581, 627
2016 SSEF Facette pg. 24 – COBALT DIFFUSION-TREATED SPINEL
2016 Spring Gems & Gemology pg. 72-72 – Hydrophane Opal Treatments
2016 DiamondPulse – The Amazing Trapiche pg. 48-49
2016 Asterism – Gems with A Star pg. 788, 797, 812, 821
2015 Journal of Gemmology 34 / 05 Cover photo and pg. 393 – “Zawadi” Sapphires
2014 Ganoksin – TucsonGemShow – Jeffery Bergman Brings a Rare Treat To Tucson, Burmese Trapiche
Sapphire
2014 Ruby & Sapphire: A Collector’s Guide pg. 254
2012 An Emerald Encryption: The Abhaya Emerald Buddha
1996 Fall Gems & Gemology pg. 117-118 Update on Madagascar sapphires
1995 Summer Gems & Gemology pg. 137-138 Kyocera plastic-impregnated synthetic opals.
1993 Spring Gems & Gemology pg. 16-17 – Update on diffusion treated corundum: red and other colors
1990 Spring Gems & Gemology pg. 100 – Diffusion treated corundum
1990 Summer Gems & Gemology pg. 115-133 –The identification of blue diffusion treated sapphires.

AGTA Spectrum Awards Honorable Mention 1988