Meet the Industry

Independent and nonprofit, GIA is considered the world’s foremost authority in gemology. Established in 1931, GIA is known as the creator of the famous 4Cs: Color, Cut, Clarity, and Carat Weight and the GIA International Diamond Grading System™, the global standard used to describe diamond quality. A leader in gemological research, GIA translates its expert knowledge into world class professional training and benchmark grading and identification services, considered the most accurate and impartial gem reports available.

Through its flagship scientific journal, Gems & Gemology, GIA publishes the latest peer-reviewed research on diamonds and colored stones, including where they are found, their special characteristics, and new techniques to identify simulants, synthetics and treatments.

GIA is dedicated to advancing gemological knowledge and upholding the highest standards of integrity. Its research, education, and grading reports serve to protect everyone who buys or sells gems.

Read articles from GIA:
Play-of-Color Opal, Gemstone Enhancement Detection: Thermal Enhancement and Diffusion Treatment