Quality Grading
Grading Colorless Diamonds
In order to assess the value of a diamond, laboratories have created a grading system used internationally since the 1950’s. This system is based on the well known 4 Cs, which are used to grade all diamonds, whether colorless or colored.
The Main Laboratories
Since the creation of the GIA in 1931, other laboratories have appeared and are now renowned institutions:
GIA (Gemological Institute of America): founded in 1931 in the US. | |
 | AGS (American Gemological Society): founded in 1934 in the U.S. |
 | GCL (Central Gem Laboratory): founded in 1970 in Tokyo. |
 | HRD (Hoge Raad voor Diamant, or Diamond High Council): founded in 1973 in Antwerp. |
 | EGL (European Gemological Laboratory): founded in 1974 in Belgium. |
 | IGI (International Gemological Institute): founded in 1975 in Antwerp. |
