Jeffery Bergman

With humble roots from a non-gem trade family, as a lapidary hobbyist, Jeffery cut and polished his first gemstone at the age of fourteen launching him on a lifelong career that has taken him to more than 70 countries, and every continent except Antarctica. With 5 decades of broad-based experience in natural gemstones, diamonds, and fine jewelry, in 2020 Jeffery founded Eighth Dimension Gems (formerly Primagem) in Bangkok, Thailand, where he has lived for over 30 years.

Proclaimed a “profound expert in gems” by the prestigious SSEF – Swiss Gemmological Institute in Basel, Switzerland, Jeffery passed requisite exams for his SSEF Basic Gemmology (BGC) Diploma, SSEF Basic Diamonds (BDC) Diploma, and completed SSEF’s Advanced Pearls (ATC), Advanced Colored Stones (ATC), and the Scientific Gemmology (SGC) Certificate for which an advanced gemmological education is a requirement in order to take the course.

Featured in many gem and jewelry periodicals, Jeffery has contributed 4 trade alerts, 5 book reviews, over 20 published articles, 22 published research contributions and 24 presentations related to gemology. He has appeared in interviews on the ABC, BBC, CCTV, CNA, CNN, NBC, and GEO. Jeffery has been quoted in Time, USA Today, National Geographic, Discover, GIA’s Gems & Gemology, Gem-A’s Journal of Gemmology, ICA’s InColor, Rivista Italiana di Gemmologia/Italian Gemological Review, and many other publications around the world.

A guest speaker at eight GIA Gem Gatherings as well as many gemological conferences & universities, Jeffery is a Senior Accredited Gemologist voting member of the AGA – Accredited Gemologists Association, an Honorary Professor for the AIGS – Asian Institute of Gemological Sciences in Bangkok, Thailand, and pro bono Vice President, Emeritus of the IGS – International Gem Society, an online gemological educational website with over 20,000 members.

Awards & Achievements


Jeffery's Contributions to Gemology

  • Honorary Professor for The AIGS – Asian Institute of Gemological Sciences.
  • Vice President IGS – International Gem Society online gemological education with over 18,000 members


2022 6th Mediterranean Gem and Jewellery Conference in Thessaloniki, Greece – Spinel: History, Origins, Treatments, Marketing and Pricing

2021 IIG – International Institute of Gemology, Bengaluru, India – Kashmir Trapiche Ruby from the Batakundi mine

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

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

2016 Mediterranean Gemmological & Jewellery Conference, Valencia, Spain – Phenomenal Prices – Market Value of Phenomenal Gems

2015 AGA Tucson Conference. Collector Gems: A Co-Evolution of Life, Minerals, and Technology

2015 GIA Gem Gathering Bangkok – Opal Treatments: 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

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

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

2011 GIA Gem Gathering Bangkok – Spinel: The Great Impostor

2011 GIA Alumni Assn. Atlanta, Georgia – Spinel: The Great Impostor

2010 GIA Gem Gathering Bangkok – Opal: Still the Queen of Gems

2009 GIA Gem Gathering Bangkok – Meteorites: Heavenly Jewels

2009 GIA Gem Gathering Bangkok – Trapiche: The Rising Star


2015 The Australian Gemmologist pg. 389-402. Ethiopian Opals: Facts, Fears and Fairytales

2016 ICA InColor Spring, Cover photo and feature article – Trapiche: The Rising Star

2022 Mid East Information, April 29, The Origin, Weight And Value Of The Burj Alhamal Ruby
Misrepresented In Potential Scam

Gems & Gemology: 

2015 Summer – Crimson Prince Ruby From Namya

2016 Fall pg. 288-287 – Co-author: Bead-cultured and non-bead cultured pearls from Lombok, Indonesia

2020 Spring – Jeffery Bergman Discusses Trapiche Gem

IGR – Italian Gemological Review:

2019 #6 – Cover photo and article: Ethiopian emeralds, a stunning discovery

2019 #7 – Opali Etiopi. Fatti, favole e paure

2020 #10 – An overview of emerald enhancements

2021 #12 – The ultimate challenge. From an 11.22-carat with minor clarity enhancement, to an

exceptional 10.17-carat oil/resin-free natural Shakiso, Ethiopian emerald

2021 # 12 – A lesson from Jeffery Bergman, a master gemologist and a world respected gem

dealer who started from the bottom by licking opals.

IGS – International Gem Society:

800 Years of Mogok: A Celebration in Tenuous Times

Emerald Myth Busters: Identifying Colombian Stones

The World’s Largest Cut Cats-eye Chrysoberyl

The World’s Largest Emeralds

Emerald Enhancements: A Consumer and Trade Guide

Fake News in the Gem Trade: A Waterworn Emerald from Chivor?

Ruby-Glass Composites vs Leaded Glass Clarity Enhancements

Is the 500-Pound Beleza Emerald Really Worth $280 million?

Emerald Transformation: Cleaning and Recutting a Natural Emerald

Gem Origin Opinions: When Gem Labs Agree To Disagree

Buyer Beware: Closer Examination of the Burj Alhamal Ruby Casts Doubt on its $120 Million Valuation



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


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 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.


Bellerophon GemLab, Bangkok/Paris

Greenland Ruby, Nuuk, Greenland on behalf of Nebari Holdings, Miami, FL

Nebari Holdings, Miami, FL

Honorary Professor for AIGS – Asian Institute of Gemological Sciences, Bangkok TH

Vice President Emeritus of the IGS – International Gem Society, an online gemological education website with over 20,000 members, Lincoln, MA


Milan Natural History Museum, Milano, Italy

American Museum of Natural History, NY, NY

Natural History Museum of Los Angeles County, LA, CA

Smithsonian National Museum of Natural History, Washington DC

Harvard University Mineralogical & Geological Museum, Boston, MA

Alfie Norville Gem & Mineral Museum – University of Arizona: Trapiche Gem Collection

University of Arizona Gem Science Department: 377 Gemstone Reference Collection