With humble roots from a non-gem trade family, as a lapidary hobbyist, Jeffery cut and sold 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 and worked for over 30 years.

Jeffery’s formal gemological training was accomplished at the prestigious SSEF – Swiss Gemmological Institute in Basel, Switzerland where he passed requisite exams for his SSEF Basic Gemmology (BGC), SSEF Basic Diamonds (BDC), Advanced Pearls (ATC), Advanced Colored Stones (ATC) and Scientific Gemmology (SGC) diplomas and certificates. SSEF Director Dr. Michael S. Krzemnicki has declared Jeffery to be “a profound expert in gems”.

Featured in many gem and jewelry periodicals, Jeffery has contributed 4 trade alerts, 5 book reviews, over 20 published articles, 22 published contributions, and 24 presentations related to gemology. He has appeared in interviews on 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 around the world, Jeffery is an Accredited Senior 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.

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