A diamond certification, also known as a diamond report, is issued by an accredited independent gemological laboratory. The report details specific information as it relates to a specific diamond. In addition to the diamond's carat weight and measurements, a certificate includes grades for the diamond's cut, color and clarity.
The issuing diamond grading laboratory has no affiliation to any retail outlet, giving the consumer a completely objective opinion on the diamond’s quality. The certification includes the exact measurements, proportions, color grade, clarity grade, cut grade and carat weight of the diamond. Each certificate details a record number, the date which it was analyzed and usually a plotting of the diamond which shows the internal and external characteristics of the diamond.
The leading diamond laboratory in the world and the one that is setting the Diamond grading standard is the Gemological Institute of America (GIA).