Established in 1998, IGS is the largest online gemology resource and community.

Our mission is to make gemology accessible and affordable.

Who are IGS members?

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

  • Aspiring Professionals
  • Curious Enthusiasts
  • Lapidaries & Metalsmiths
  • Collectors & Private Dealers
  • The IGS Team

    The management and advisory team at IGS is a diverse group of professionals committed to delivering our mission.

    Donald Clark, CSM IMG

    The late 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.”

    Jeffery Bergman, SSEF SGC
    Vice President Emeritus

    Jeffery Bergman, SSEF SGC, founder and director of 8th Dimension Gems in Thailand, 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.

    Lisa Rosen
    Company Management

    In 2012, Donald Clark retired and passed along stewardship of the IGS to the Rosen family, who were longtime members of IGS. Lisa Rosen runs the day-to-day operation of IGS and The Ganoksin Project, a technical resource website for bench jewelers and jewelry manufacturers. Lisa strongly believes that IGS must remain a cost-effective, accurate, and comprehensive resource for all those interested in gemology. IGS is our passion, and it is a family business.