Diamond certification is the assurance of quality. A certification is a detailed diamond quality report that has been issued by an accredited gemological laboratory. It gives proof that a choice diamond has undergone an unbiased professional examination.
Some retailers make use of in house appraisals, rather than certification from laboratories. The accuracy of an appraisal depends on the knowledge, skill, and training of the appraiser. For that reason, appraisals are not as accurate as a certified diamond quality report.
The Most Trusted Laboratories
In both the GIA and AGS labs, diamonds are evaluated by highly trained graduate gemologists. These two labs are the most trusted in the world and are recommended by all important diamond brokers. The Diamond Broker uses only these two most respected laboratories.
The Gemological Institue of America:
Diamond certification documentation from the GIA will provide detailed laboratory findings for the following characteristics of the stone under evaluation:
Weight, Shape, Cutlet Size, Clarity Grade, Color Grade, Fluorescence, Plot of Internal and External Inclusions, Girdle Thickness, Depth Percentage, Table Percentage, Polish, Symmetry and will include comments about each diamond.
A certificate from the GIA will look like the one shown here, left.
See also: The GIA
The American Gem Society:
AGS diamond quality reports are very similar to those from the GIA. We posted one for you here, left.
AGS certificates provide details for the following:
Description, Weight, Shape and Cut, Depth Percentage, Pavilion Depth Percentage, Polish, Symmetry, Clarity Grade, Color Grade, Cut Grade, Crown Angle, Crown Height Percentage, Table Percentage, Pavilion Angle, Girdle Thickness, Cutlet Size, Fluorescence, Plot of Internal and External Inclusions, and comments about the diamond.
See also: The AGS