Diamonds

Established in 1931, GIA is the world’s largest and most respected nonprofit institute of gemological research and learning.

GIA discovers (through GIA Research), imparts (through GIA Education), and applies (through the GIA laboratory and GIA Instruments) gemological knowledge to the public. With 1,200 employees, the Institute’s scientists, diamond graders, and educators are regarded as the world’s foremost authorities in gemology.

GIA is the creator of the revolutionary 4Cs of diamond value (carat, color, clarity, and cut).  It is also the birthplace of the International Diamond Grading System™. Today, GIA’s D-Z color-grading scale, Flawless–I3 clarity-grading scale and Excellent-to-Poor cut-grading scale are recognized by virtually every professional jeweler and savvy diamond buyer in the world.