Loose diamonds (not pre-set in a ring or other setting) that have been certified by GIA (Gemological Institute of America) or AGS (American Gem Society).
A certificate is a “blueprint” of a diamond, it tells you the diamond’s exact measurements and weight, as well as the details of its cut and quality. It precisely points out all the individual characteristics of the stone. Certificates also serve as proof of the diamond’s identity and value.
A certificate is not the same thing as an appraisal. A certificate describes the quality of a diamond, but it does not place a monetary value on the gem. An appraisal places a monetary value on your diamond, but does not certify the quality of the diamond.
There are many diamond labs that issue certificates, but the Gemological Institute of America (GIA) and the American Gem Society (AGS) are the two most widely regarded and recognized diamond grading labs in the world.
Not all diamond certificates are created equal. If you opt to buy non GIA- or AGS- certified diamonds, always ask for credentials of the certifying lab.
And while there are many other diamond grading labs in operation (many of which produce their own grading reports), different labs have different grading standards, and some labs will be more lenient with their standards than others.
Therefore, we recommend buying from a diamond jewelry store that offers GIA or AGS certified diamonds, as these labs have consistently demonstrated their commitment to high standards.
If you do elect to buy non GIA- or AGS- certified diamonds, always ask for credentials of the certifying lab.
Shopping for certified diamonds allows you to make an informed choice about your diamond selections and to comparison shop among various diamond merchants.
You can compare one diamond with a particular weight and quality with other diamonds of similar weight and quality to determine which diamond is the better value — or which merchant has the best prices.
[NOTE: If a jewelry store offers to sell you a loose diamond without a certificate, keep in mind that it means you are buying the diamond based only on the salesperson's claim about its quality, and that a trained gemologist or even other jewelers may disagree with the salesperson's assessment.]
Loose diamonds are readily available in a wide variety of shapes including: Round Brilliant, Asscher Cut, Cushion Cut, Princess Cut, Emerald Cut, Radiant, Oval, Pear, Marquise, and Heart shaped.
Not sure which shape is right for you? Learn more about Diamond Shapes here.
Read more about the Four Cs of Diamonds
4Cs of Diamond Grading | Diamond Cut | Diamond Clarity | Diamond Color | Carat Weight | Diamond Certificates | Diamond Size Chart | Diamond Fluorescence | Diamond Ring Settings | Diamond Glossary
General Shapes Information | Asscher Cut Diamonds | Cushion Cut Diamonds | Emerald Cut Diamonds | Heart Shaped Diamonds | Marquise Cut Diamonds | Oval Diamonds | Pear Shaped Diamonds | Princess Cut Diamonds | Radiant Cut Diamonds | Round Brilliant Diamonds