The Gemological Institute of America (G.I.A.)

G.I.A. is the world`s most famous and reputable laboratory. The department of G.I.A dealing in the diamond certifications is G.I.A.'s Gem Trade Laboratory. The G.I.A. provides very careful diamond quality reports, in which the description of all the possible diamond flaws, their position, size and shape is contained. The G.I.A. is extremely strict in its grading. If the quality of a diamond is on the border between the higher and the lower grade, the G.I.A. always assign the lower grade. G.I.A. operates with a Sarin proportion analyzer, a computer electronic measuring device, aimed to set the proportions of a diamond.

A new Dossier certification has become used by G.I.A. recently. It is a miniature variant of the typical complete G.I.A. diamond quality report with the exception of the blemishes and inclusions data. However, G.I.A. does later include the edge or girdle of the diamond with the G.I.A. diamond quality report number for identification purposes. The Dossier certification is lower in price and is frequently used for smaller diamonds grading.