Gemological Science International (GSI) is the only major gemological organization established in the 21st century. Founded in 2005 in New York City, it has grown to become one of the largest gemological entities in the world with laboratory facilities spanning four continents.

Utilizing cutting-edge processes and proprietary technologies, along with a commitment to the highest ethical and responsible standards, GSI provides manufacturers and retailers globally with a wide range of grading reports and services for diamonds (both natural and lab-grown), colored gemstones, and jewelry. GSI is the leader in the testing and detection of undisclosed lab-grown diamonds in finished jewelry. The company also offers a variety of educational programs to the trade and has a dedicated internationally recognized team of researchers, scientists, and professionals committed to advancing gemological research in the industry.

Gemological Services

Diamond & Jewelry Grading Reports

GSI offers diamond and colored stone grading reports designed to meet your needs. All grading reports are available in a variety of formats.

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Research & Education

GSI established its Research & Education Center to share important developments in the global gem and diamond industries, and further educate both the trade and consumers.

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Testing & Detection

GSI’s leading screening and detection process ensures accurate results to meet the needs of transparency and disclosure.

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