Tom Moses Leaving GIA After Nearly 50 Years

Tom Moses examining the 2,488-carat “Motswedi” diamond at GIA’s laboratory in Gaborone, Botswana, in July 2025. After five decades with the Gemological Institute of America, Moses will leave the lab in May. He will be named GIA’s chief of gemological research, emeritus in honor of his years of service and his contributions to gemology. (Image courtesy of GIA; Photo credit: Wuyi Wang)

Carlsbad, Calif.—The Gemological Institute of America announced that Tom Moses, who has been with GIA for almost 50 years and has become a key figure in modern gemology, will be leaving GIA in the spring.

In a news release about Moses’ departure sent out Thursday, the lab said both it and Moses have been preparing for his departure for the last few years.

He will remain with GIA through May.

During this time, GIA said Moses will work with its research and laboratory teams to further enhance its research efforts, support its clients, and advance its mission.

A lab spokesperson said there are no plans to appoint someone new to Moses’ exact role, executive vice president and chief laboratory and research officer.

To honor his contributions over the years, GIA will name Moses chief of gemological research, emeritus.

“The rigor Tom brought to grading, the discipline he brought to science, the unwavering focus he brought to our customers, and the humility he brought to leadership reflect the very best of what we aspire to be,” GIA President and CEO Pritesh Patel said.

“Fifty years is not simply a measure of time—for GIA, it has been a period of remarkable growth driven by Tom’s commitment, curiosity, and leadership. His lasting legacy lives in the standards he helped shape and the generations of professionals he guided and inspired.”

Moses joined GIA’s laboratory in Santa Monica, California, after earning his Graduate Gemologist diploma in 1976. (GIA left Santa Monica for Carlsbad, California, in the late ‘90s.)

He went on to work under his mentor, gemologist Robert Crowningshield, in New York City.

Moses has held numerous leadership roles at GIA over the years, including senior vice president and executive vice president, according to his LinkedIn page.

He also has co-authored more than 100 technical articles for GIA’s professional journal Gems & Gemology and other peer-reviewed journals.

GIA said Moses was the driving force behind its international expansion, transforming GIA into a global leader in gemology and education with 10 laboratories and seven schools across 10 countries.

In 2002, Moses’ leadership was recognized with the Richard T. Liddicoat Award for Distinguished Achievement.

In 2013, he was elected to GIA’s board of governors. At the same meeting, he was promoted to his current role, executive vice president and chief laboratory and research officer.

“I have been extremely privileged to work with the two greatest gemologists and have them as my mentors,” Moses said.

“I will always be grateful to Richard Liddicoat for hiring me and for his selfless guidance, and to Robert Crowningshield, with whom I worked closely for 20 years, for sharing his extraordinary knowledge and for his friendship. There is no better way to honor their legacy than through continued research that advances our understanding of Earth’s treasures.”