A diamond grading certificate is a report given by an independent and professional gemological laboratory. The diamond is evaluated for its quality, not its value. Every diamond is unique, to search diamonds that are identical is impossible. The certificate will map out all the diamond’s recognizable and individual characteristics. Each certificate will include the diamond’s color, clarity, carat weight and cut information (see the 4 C’s). The grading report also includes a hand-drawn map of the diamond’s inclusions. Since no two diamonds are exactly alike you can always check that the certificate matches the diamond.
A certificate is not the same thing as an appraisal. A certificate describes the quality of a diamond, but it does not place a monetary value on the gem. An appraisal places a monetary value on your diamond, but does not certify the quality of the diamond.
Who Issues Certificates? There are many diamond labs that issue certificates, but the
Gemological Institute of America (GIA) and International Gemological Institute (IGI)
are the two most widely regarded and recognized diamond grading labs in the world.
See a Sample of a GIA certificate