The most important step in choosing a diamond to purchase is to review a copy of that diamond's certification. A diamond certificate documents your diamond's quality characteristics and becomes your guarantee of its identity. A diamond with certification has been scrutinized under a microscope by a gemologist who has analyzed its 4 Cs, its dimensions, finish, symmetry, and other characteristics. Diamond certificates are also known as grading reports.
If you choose to buy a diamond without certification, keep in mind that you are buying the diamond based solely on someone's claim about its quality. A trained gemologist may disagree with that person's assessment. Certificates
Every loose diamond sold by our company has been analyzed and graded by either the Gemological Institute of America (GIA) or the American Gem Society Laboratories (AGSL). As two of the most respected laboratories in the diamond industry, these labs are known for the most consistent, strict and unbiased systems for grading diamonds.
Note that a certificate, or grading report, is not the same thing as an appraisal. Your diamond’s certificate describes the diamond’s quality characteristics, but it does not place a monetary value on the gem like an appraisal does. As a complete evaluation of your diamond, it includes information on the 4Cs, including:
Your diamond’s color grade, clarity grade and carat weight
The diamond’s cut quality (not all reports grade cut)
An evaluation of the diamond’s symmetry and polish
It also may comment on the diamond’s fluorescence, girdle and culet
grading report also includes a diagram that “maps” the diamond's inclusions. Since each diamond is unique, the diagram acts like a fingerprint to identify that particular diamond. Here is a sample diamond AGSL grading report.