GIA’s laboratories use advanced instrumentation and research to deliver accurate grading, identification, and origin ...

Gemstones are valued based on the Four Cs - color, clarity, cut, and carat. Precious stones include diamonds, sapphires, ...

A public benefit, nonprofit institute, GIA is the leading source of knowledge, standards, and education in gems and jewelry. Welcome to GIA. Students around the globe turn to GIA for the knowledge, ...