Diamond Certificates

Diamond certificates from independent organizations such as the Gemological Institute of America (GIA) provide a diamond grading report, that gives you valuable information about the 4 C's that were taken into consideration when the diamond was priced. It's important that you use an outside source for diamond certificates, instead of the jeweler who is selling the diamond you are interested in, because the jeweler wants to make money on the sale of the diamonds, the certificates may be slightly biased and you could be paying more than the market value of the diamond.
When you go to a jewelry store, or consider making a purchase from an online retailer, the jewelry that has diamond certificates tends to sell for several hundred dollars more than diamonds that are graded the same that are without certificates. This is because the jeweler recognizes that they typically grade their diamonds one level better than an independent grading organization, like the Gemological Institute of America. The GIA is more conservative when grading diamonds because they do not gain anything from diamond sales.

Diamonds are valued according to their quality based on a grading system that makes use of the 4 C's. You should receive diamond certificates (also called grading reports) from independent companies rather than a jeweler, to insure that your getting an unbiased reporting of the value of the diamond. Otherwise, you could be paying much more for your diamond than what the diamond is actually worth. A diamond appraisal without a certificate might be meaningless.