Dr Shihaan Larif
A diamond grading certificate is defined as a document which proves that some of the physical properties of the diamond has been tested by professionals in an independent laboratory.
Nowadays most individuals who shop for diamonds ask for diamond certificates before buying the stone. This is a very good trend as it protects the diamond consumers. It also allows consumers to compare the prices of diamonds of similar grade from different stores.
To produce a diamond certificate, the diamond undergoes a thorough examination by experienced personell in a gemological laboratory.
The diamond is examined by the experienced eye of a gemologist,followed by examination using a ‘jewelers loop’, microscopes and other modern equipments. In addition to the 4c’s (Carat weight, color, clarity and cut) the diamond is also examined for its dimensions, polish and symmetry. An illustration is usually made on the inclusions of the diamond.
Most reputable websites selling diamonds have put up their diamond certificates online for customers to view. Many offline shops have diamond certificates for their diamonds, do not forget to ask for one.
Sample’s of a Damond Grading Reports
Sample of a ‘Diamond Grading Report’ issued by the GIA- Gemological Institute of America.
Sample of a ‘Diamond Quality Report’ issued by the AGS- American Gem Society Laboratory.
Important: A Diamond Certificate does not provide the value of the diamond
A diamond certificate is not the same as ‘Appraisal’. The monetary value of a diamond is not determined during the testing process and therefore it is not placed on the certificate.
On the other hand an ‘Appraisal’ determines the monetary value of the diamond but it does not certify the quality of the diamond.
What is a Diamond Dossier?
This is a special type of diamond grading report issued only by the Gemological Institute of America.
The information provided by a diamond dossier is the same as the information on a GIA diamond grading report, excluding the plotted diagram.
A Diamond Dossier can be issued by the GIA for natural diamonds weighing 0.15 carats to 1.99 carats and in the D to Z color range.
The diamond dossier also has a special added security feature, a microscopic laser inscription of the serial no of the report on the girdle of the diamond.
Sample of a GIA Diamond Dossier
How to Read a Diamond Grading Report?
I will briefly describe the most important aspects of a diamond grading report and how to read it.
For illustration purposes I will use examples from the GIA Diamond Grading Report. However please note that all major laboraties provide the same details.
1) The Name of the Laboratory.
Eg. GIA, AGS Laboratory etc. Please dont forget to review my recommendation on ‘Diamond Buying FAQ No 5’ on this page.
2) Report No
Also known as certificate no and diamond grading certtificate no.
Every laboratory provides a unique certificate/report no. The report no is unique for the diamond. This no. also makes it easy for labs to archive copies of all certificates issued. They can also reissue a certificate if you can provide the number.
The certificate number is provided at the top and left side of a GIA Certificate.
The AGS Diamond Report no. is found on the top left hand side of the certificate.