The Gemological Institute of America (GIA) is an independent non-profit institute that is widely considered as the standard-bearer when it comes to diamond certificates. It is the GIA that established the 4C as the main criteria for assessing and describing a diamond’s quality.
The GIA’s activity is largely centered around education of jewelers as well as clients. Established in 1931, the institute defines itself as the “world’s foremost authority on diamonds, colored stones, and pearls.” Besides educating those pursuing careers in the jewelry business, gemological research and protection of quality standards are the GIA’s main fields of operation.