Diamond Certification Terms

Basics of diamond certification covering the diamond grade report, certification process, 4 Cs and flaws.

Diamond certification is also known as a diamond grade report. This is a fairly straightforward process by which a diamond is measured and tested. The results of this scientific study of a particular diamond are recorded in a report that accompanies the diamond. This report, or certification, serves as an identifier or fingerprint for the particular diamond, as no two diamonds are alike.

The certification process is carried out by a gemological laboratory. Gemological laboratories should be independent of any diamond retailers or wholesalers, to avoid any conflict of interests or bias. The gemological laboratory will take the diamond, loose only, and measure its various attributes and dimensions. Amongst the loose diamond's particulars that are measured are the 4 Cs of Cut, Colour, Clarity and Carat. The diamond's flaws (or inclusions) are noted and, depending on the laboratory grading the diamond, can be plotted on a diagram of the diamond. The laboratory then produces the paperwork and sends it on, accompanying the diamond for which it was prepared. It must be noted that not all gemological laboratories are equal in either their costs or their grading results.

There are many different gemological laboratories available to the diamond-buying public. Some of the more well known, respected and trusted are the following: GIA (Gemological Institute of America), AGS (American Gemological Society), HRD (Hoge Raad Voor Diamant; Diamond High Council), PGS (Professional Gem Sciences), EGL (European Gemological Institute) and the IGI (International Gemological Institute). Each of these has there own criteria and method of grading loose diamonds, but they all operate within a high set of parameters, in regards to grading a diamond's attributes and dimensions. Be aware that as each has its own methods, each also has its own expense guides for preparing a certificate.