Established in 1931, the Gemological Institute of America is the world’s foremost authority on diamonds.
In 1953, the GIA created its International Diamond Grading System, which specifies uniform criteria for grading diamonds. The GIA grading system is recognized worldwide, and diamond manufacturers from around the globe send diamonds to the GIA’s laboratories for examination and grading. Currently GIA account for more than 40% of the diamond report issued worldwide. Robert M. Shipley, founder of the prestigious school of gemology, the Gemological Institute of America (GIA) is also the founder of American Gem Society. In the US, people regards AGS and GIA as sister company aiming at very different level of consumers