About IGS Members

A society is about people that are interconnected. Here at IGS, gems have brought us together. IGS has members on every continent (except Antarctica) who range from seasoned professionals to the merely curious.

Professionals join IGS because gems are their favorite topic. We offer them the Gem Pricing Guide, an email newsletter, a Reference Library and advertising privileges. The professionals in our organization are important for sharing their wealth of knowledge. No one individual has the experience of the membership as a whole.

On the other hand, some of our members have no interest in working in the gem and jewelry trade and are merely curious. They simply want to unravel the mysteries surrounding their gems. Nowhere else can a person access so much information from an unbiased source.

In between, we have many lapidaries, metal smiths, collectors, private gem dealers, and a variety of merchants. Some of our members are making mid-life career changes; others are students planning for the future.

IGS was initially founded to make gemology information accessible and affordable to everyone. Members can enroll in our gemology course and take the complete course through to certification. Now, the mission has evolved to bringing together people who want to learn, discuss and trade gemstones. Come join our community!

About the Founder

Donald Clark, CSM

Posing with some Quartz

Donald Clark, CSM founded the International Gem Society in 1998. Donald started in the gem and jewelry industry in 1976. Throughout his career he served as a wholesaler and retailer of gemstones and finished jewelry. He received his formal gemology training from the Gemological Institute of America (GIA) and the American Society of Gemcutters (ASG), founded by the late Dr. Gerald “Jerry” Wykoff.

The letters “CSM” after his name stood for Certified Supreme Master Gemcutter, a designation of Wykoff’s ASG which has often been referred to as the doctorate of gem cutting. The American Society of Gemcutters only had 54 people reach this level. To become a Certified Supreme Master Gemcutter, the lapidary must have passed a written exam and scored better than 99.7% on two stones entered in competition. When citing Mr. Clark’s work in our articles, IGS still uses the original designations from Wykoff’s ASG, despite that organization having ceased operating after Dr. Wykoff’s passing.

Along with dozens of articles for leading trade magazines, Donald authored “Modern Faceting, the Easy Way.” This describes a method of faceting he developed. It greatly reduces the time needed to facet fancy shaped gems. It meets a real need in bringing the labor of custom gem cutting closer to the faster, but lower quality factory work. Unfortunately, in 2020 Donald Clark passed away.

About Company Management

In 2012, Donald Clark retired and passed along stewardship of the IGS to Seth and Lisa Rosen.  Seth and Lisa were longtime members of the IGS.  Seth is a gem collector and active Internet entrepreneur, who had already spent a great deal of time in the custom jewelry business. He founded CustomMade, the world’s largest online custom jeweler and also operates The Ganoksin Project, a technical resource website for bench jewelers and jewelry manufacturers. Seth and Lisa felt strongly that the IGS needed to remain a cost-effective, accurate, and comprehensive resource for all those interested in gemology.  IGS is our passion, and it is a family business.

Seth and Lisa Rosen

Seth and Lisa Rosen

Current Mailing Address:

International Gem Society, LLC
145 Lincoln Road
PO Box 466
Lincoln, MA 01773

Contact Us Via Email Here

Technical Advisors

IGS would not be where it is today without the incredible contributions of many amazing contributors.

Jeffery Bergman – Jeffery Bergman, SSEF, SGC was a contributor to the IGS long before Seth and Lisa were involved.  Aside from Don Clark, he is the longest-standing contributor to IGS.  In honor of over 20 years of friendship and support, Jeffery holds the honorary title of Vice President, Emeritus – International Gem Society.  He is, and always has been, a fully pro-bono contributor and maintains no financial interest in IGS.

Jeffery is founder and director of Primagem in Thailand. He is an American gem dealer with more than 40 years of experience in gemstone and fine jewelry mining, cutting, wholesaling and retailing. His career has taken him to more than 50 countries and every continent except Antarctica. He has appeared on the BBC, CNN, NBC, ABC and GEO; and has been featured in Time, USA Today, National Geographic, Gems & Gemology and Discovery Channel magazine. He is a regular guest speaker at gem lab seminars and gemological association conferences and universities.

 

Testimonials

Hello Don,

Just wanted to thank you for the fantastic adventure I have had since becoming a member of IGS. The quality of your Gemology Course is tops. Nice to know that such folks as you exist. What a gift you give, passing this knowledge along to those of us who are seekers.

Thanks again,

Dr. John Parrott

Don Clark,

You are one heck-of -a-writer. This course is so well written, that I’m convinced that anyone, even me, can understand and master this material. After having read the first four introductory articles, I find myself actually wanting more time to study. It’s like a good who-done-it mystery. It just can’t be “put down.”

Thanks

Joe

Dear Don,

I am writing this e-mail specially to extend my most grateful thanks to you (in fact on behalf of all the IGS members) for the variety of invaluable New Year Gifts you have accorded to the members for 2006. I feel, your dedication to “bringing quality information and educational services to everyone interested in gemstones” is truly one-of-its-kind. I, and most probably many other members too, owe our gemology knowledge to IGS. You are indeed our “Guru” in the true sense of the term. Your knack of simplifying the most complicated topics and your constant endeavor to update the existing information are really unique. Since, as you said you have more planned for this year than you will be able to complete, I wish God gifts you longer days which have 42 hours instead of the usual 24!

Thanking you once again and with Best Regards,

Nitin Pawaskar, Pune, India

Dear Don,

I have been on the distant sidelines of the jewelry business for a long time with a great love of colored stones and working with gold. I am committed to getting into the field full-time and even being self-employed and recognize the need for the credentials. I must tell you that IGS is a Godsend for me, as I do not have the resources or the six months required to get a GG from the GIA now. I really appreciate being part of the organization.

Thank you again

Sincerely,

Charlie Bernheiser

Don,

I want to personally commend you on your article in the summer issue on the polariscope. I have told you I am self taught with only reference material. I am still trying to learn what I am reading from the article. Thank you for the lesson. This one article is worth five times the membership to IGS!

Thank You

A.C.Hughes, Panache’ Gems

Don,

I have never known or heard of an organization that offers so much for its members, and at such a low cost. You are so honest and helpful to the members. I hope you get the recognition that you deserve. What started as a hobby in 1998 and now is a small home business for my wife and I (we also have day jobs and two young children), has been made so much easier by the information you supply.

Thank You

Ernest and Peggy Roisch, Rainbow Rocks, LTD.

Hi Don,

Thanks for all the effort and work on IGS. It has helped me tremendously in many different aspects of my business, from faceting to pricing and even historical anecdotes that I can share with people at shows. I really appreciate what you are doing.

Thanks again,

John Lemieux Rose, 2 Roses Studios

Dear Mr. Clark

My sincere thanks for your time in providing the information! Everyone I asked had a clever “answer” which mostly included the much-touted “C” advisory put out by the diamond industry. Made it sound like a closely guarded secret known only to jewelers. I am only a humble collector (mostly garnets) seeking to provide practical information to my broker.

Thank you for encouraging an infant love of gemstones and for being so democratic in promoting the hobby. I have met with a lot of subterfuge. Your attitude is very refreshing and much appreciated.

Mrs. Donna Lambert

Dear Donald,

You know the best thing that I have learnt from your great courses is that it does not matter how much you think you about gems, you never stop learning, each day there is something more learn, it will never stop. Thank all for the help, education and support that you give IGS members.

Peter Checkley, One Very Proud Member

Dear Don,

Thank you for marking my exam as quickly as you did. I’ve spent a
tremendous amount of time and energy in preparing for this exam. I am very pleased with my results.

I found the couse material to be very complete and up to date. The exam
format forced me to review the course material over and over. I now feel I
have a pretty good handle on gem theory due to this format.

Christopher

Our Founder, Contributors, and Technical Advisors

Donald Clark, Founder

Donald Clark, CSM, founded the International Gem Society in 1998. Donald started in the gem and jewelry industry in 1976. He received his formal gemology training from the Gemological Institute of America (GIA) and the American Society of Gemcutters (ASG). The letters "CSM" after his name stood for Certified Supreme Master Gemcutter, a designation of Wykoff's ASG which has often been referred to as the doctorate of gem cutting. The American Society of Gemcutters only had 54 people reach this level. Along with dozens of articles for leading trade magazines, Donald authored the book Modern Faceting, the Easy Way.

Jeffrey Bergman, Vice President Emeritus

Jeffery Bergman SSEF, SGC, is the longest-standing contributor to IGS. He is, and always has been, a fully pro-bono contributor and maintains no financial interest in IGS.

Jeffery is founder and director of Primagem in Thailand. He is an American gem dealer with more than 40 years of experience in gemstone and fine jewelry mining, cutting, wholesaling, and retailing. His career has taken him to more than 50 countries and every continent except Antarctica. He has appeared on the BBC, CNN, NBC, ABC, and GEO, and has been featured in Time, USA Today, National Geographic, Gems & Gemology, and Discovery Channel magazine. He is a regular guest speaker at gem lab seminars and gemological association conferences and universities.

Dr. Joel Arem, Contributor

Dr. Joel E. Arem, PhD, FGA, has more than 60 years of experience in the world of gems and minerals. After obtaining his Ph.D. in Mineralogy from Harvard University, he has published numerous books that are still among the most widely used references and guidebooks on crystals, gems and minerals in the world.

Co-founder and President of numerous organizations, Dr. Arem has enjoyed a lifelong career in mineralogy and gemology. He has been a Smithsonian scientist and Curator, a consultant to many well-known companies and institutions, and a prolific author and speaker. Although his main activities have been as a gem cutter and dealer, his focus has always been education. JoelArem.com

Fatma Oya Borahan, Contributor

Fatma Oya Borahan, GG, FGG, has Graduate Gemologist and Diamond Diplomas from the Gemological Institute of America (GIA) the German Gemmological Association (DGemG) and Gemmological Association of Great Britain (GemA). birdamlasu.com

Barbara Smigel, Contributor

Barbara Smigel PhD, GG, is a GIA certified gemologist, facetor, jewelry designer, gem dealer, gemology instructor, and creator of the well-regarded educational websites acstones.com and bwsmigel.info.

Addison Rice, Staff Writer

A geologist, environmental engineer and Caltech graduate, Addison's interest in the mesmerizing and beautiful results of earth's geological processes began in her elementary school's environmental club. When she isn't writing about gems and minerals, Addison spends winters studying ancient climates in Iceland and summers hiking the Colorado Rockies.

Gerald Wykoff, Contributor

Dr. Gerald Wykoff was a GG (Graduate Gemologist), a CSM (Certified Supreme Master gemcutter), educator, and author of several gemology books. He founded the American Society of Gemcutters in the 1980s and served for more than 10 years as the editor of its monthly magazine, American Gemcutter.

Jeff Graham, Contributor

The late Jeff Graham was a prolific faceter, creator of many original faceting designs, and the author of several highly-regarded instructional faceting books such as Gram Faceting Designs.

Bear Williams, Contributor

Bear Williams, CG, FGA (Hon), is President and Laboratory Director at Stone Group Laboratories. Bear travels to gem producing countries and treating regions researching the latest trends in gemology and visiting with other lab directors. On-site research allows him to keep abreast of new synthetics and treatments in the marketplace. He regularly meets with other gemological associations and labs, and together will present research findings, and discuss the latest nomenclature or laboratory issues relevant to the trade and consumers. Recognized as an expert in the field of digital spectroscopy, Bear operates UV-Vis-NIR, ED-XRF, FTIR, UV, and Raman Spectrometers.

Cara Williams, Contributor

Cara Williams, FGA, is Vice-President and Senior Staff Gemologist at Stone Group Laboratories. Cara is a fellow of the Gemmological Association of Great Britain (Gem-A). She has been a tutor for the prestigious Diploma in Gemmology course for the Gem-A in London for more than 15 years. Growing up in a retail jewelry family with a concentration in colored stones, Cara has been in the wholesale trade since 1986. She brings a lifetime of experience working with gems to the lab, her students, and many published articles.

Megan Coward, Staff Writer

Megan Coward GG, GJG, is a graduate of the GIA with Graduate Jeweler Gemologist and Graduate Gemologist accreditations. She has 20+ years in the retail jewelry industry in various roles including as a diamond buyer and gemstone appraiser.

Phoebe Shang, Staff Writer

A gem lover and writer, Phoebe Shang, GG, holds a graduate gemologist degree from the Gemological Institute of America and masters in writing from Columbia University. She got her start in gemology translating and editing Colored Stone and Mineral Highlights for a professor based in Shanghai. Whether in LA, Taipei, or New York, Phoebe spends her time searching for gems to design and being lost in good books.

Kyrylo Gubariev

Kyrylo Gubariev, Graduate Gemologist (GG, AJP) is a gemologist with a passion for sharing his knowledge with fellow gem lovers. Originally from Ukraine, he is currently based in Bangkok, Thailand.