The term “certified diamond” is used often, but many people don’t know its exact meaning. Let’s see what a diamond certificate is, what information it contains, and why it is important for a diamond to be certified.
What Is a Diamond Certificate?
A diamond certificate is a document describing the most important quality features of a particular stone.

One of the roles of a diamond certificate is to provide third-party verification of quality.
The certificate is issued in the form of a report and includes the stone’s characteristics that have been measured and evaluated by trained gemologists.
Who Issues Diamond Certificates?
Diamond certificates are usually issued by grading labs, which are organizations that are engaged in scientific research and provide grading services for a fee to diamond vendors or individuals.
Here are some of the most reputable labs:
– G.I.A. (Gemological Institute of America)
– A.G.S. (American Gem Society)
– E.G.L. (European Gemological Laboratory)
– C.I.B.J.O. (Confédération International de la Bijouterie, Joaillerie, Orfèvrerie des Diamants, Perles et Pierres; also known as the World Jewelry Confederation)
– I.G.I. (International Gemological Institute)
The certificates issued by these labs contain mostly the same information. However, they usually differ in the level of detail provided as well as the scales used to assign grades (each lab employs different standards for evaluation).
What Information Does a Diamond Certificate Contain?
A diamond certificate (also known as a grading report) contains the most important information for determining the quality of a diamond.
For example, the report will include descriptions of the stone’s color, cut, clarity, along with grades assigned to each of these characteristics.
The report will also contain information on the exact carat weight of the diamond as well as the values of the stone’s most important measurements that help to determine how symmetrical the diamond is.
Why Diamond Certification Is Important
One of the roles of a diamond certificate is to provide third-party verification of quality. It is therefore very important for the grading report to be issued by an independent organization that is not controlled by the vendor.
Sellers can tell you anything about the quality of a certain diamond, but it goes without saying that they are likely to be biased.
However, if the stone is certified by a reputable grading lab, you can easily check how close the claims of the vendor are to the truth by examining the diamond’s certificate.
This is why you should always buy certified diamonds – reading the document will inform you what exactly you are buying and help you to avoid overpaying for a stone that should be priced lower because of its quality.
Difference Between a Diamond Certificate and an Appraisal
Diamond certificate and appraisal are terms that are often confused. An appraisal is a document that puts a monetary value on a diamond (or a piece of jewelry); it is often used to determine how much you should pay for the insurance of the stone.
A diamond certificate, on the other hand, does not value the stone in dollar terms; the purpose of this report is to document key quality characteristics, without giving an opinion on how much the diamond should cost.
Buying Certified Diamonds: What You Should Pay Attention To
When shopping for diamonds, you should not only check if the stone you are buying is certified, but also make sure that the certificate is issued by a reputable grading lab that is independent of the seller.
The most important characteristics you should be looking at when reading the certificate are the diamond’s color, cut, clarity, and carat weight: These features determine how white, brilliant and clean the stone will look, as well as how much you will have to pay for it.
To make sure that the diamond you are looking at is the same as the one described in the certificate, you can check the stone’s inscription, which is a combination of letters and numbers usually engraved with laser on the edge of the diamond.
This inscription can be seen with a loupe and should match the diamond’s serial number on the report. Not all certified stones have a laser inscription, but inscribed diamonds are preferable because they can be identified more easily.
Where to Buy Diamond Jewelry?
We recommend James Allen (read review) because you can see a 360-degree video for any diamond before buying it.
Blue Nile is another reputable diamond retailer we recommend.