The diamond certification.


Each diamond, when it is mined as rough until the final customer, is always accompanied by a classification. If this classification is confidential i twill be formulated in technical terms to be used by professionals traders during transactions to let them to quickly determine the quality of diamonds. When the classification is formal it is called "gemological testing or certification."

Here we will talk only of the parameters to grading a polished diamond and not those used to grading rough diamonds. The criteria for gemological analysis to grading a polished diamond were defined in 1953 by the GIA (Gemological Institute of America). It’s non-profit educational institute founded in 1931 in Los Angeles by Mr. Shipley, jeweler, to garner support for gemological training. In addition to the gemological laboratory GEM LAB, GIA mainly provides gemological training and confers the world’s most prestigious degree in gemology field: Graduate Gemologist, GG GIA.

A gemological grading report must refer to the international standards introduced by GIA which are usually synthesized in the 4 "C’s": CUT, CLARITY, COLOR and CARAT. If we set 100 as basis price of a diamond, the cut counts for 40% and the other 3 factors 20% each.
The gemological analysis or certificate of a diamond is not an appraisal, but it lets a professional diamantaire to arrive to a value. So the gemological certificate furnished with a diamond must be respected and internationally recognized, especially for those who buy a diamond for investment purposes (link IDC), otherwise when you will decide to sell your diamond you might have some unwelcome surprise!

There are many different gemological laboratories in the world that issue certificates, but the most reputed in the world is the certificate issued by the GIA.
Often diamonds are equipped with alphanumeric laser inscription on the girdle to link the stone to its gemological certificate. Sometimes diamonds are sealed to not compromise the integrity of the certification, even if at the diamond exchanges are obviously traded not sealed diamonds.



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