There’s a lot to learn when shopping for a diamond. We’ve all heard of the four c’s, which include carat weight, cut, clarity and color. But, in reality, there’s a fifth “C” of diamonds – certification, which is another area in which you need to be well versed. Here are the things you need to know about a diamond’s certification.
Diamond Certificates Authenticate Your Diamond
Having a certificate on your diamond verifies the other four c’s of carat weight, cut, clarity and color. Your diamond certificate will list these attributes about your diamond. The certificate will also contain a unique number, which is also engraved on the girdle of the diamond. The certificate ensures you that the diamond really has all the attributes that have been described to you by the salesperson. It gives you peace of mind and comes in handy if you ever sell the diamond.
Only Loose Diamonds are Certified
Diamonds are certified before being set, to allow the certifier to get the best look at the stone. However, you may purchase a certified diamond that has already been set into a piece of jewelry, or you may purchase from a jeweler that allows you to choose your diamond and setting separately.
There are Several Certifying Agencies
Several certifying agencies are used in the United States. The two most respected are:
- Gemological Institute of America (GIA) – The GIA is actually the body that created the “four C’s” of diamond buying.
- American Gem Society Laboratories (AGS)
If your diamond is certified by either of the agencies, you can feel confident in the certification. There is also a certifying agency in Europe, called the European Gemological Laboratory (EGL). This is a “for profit” company and is known for having a less stringent grading scale than the other agencies. Most reputable American jewelers avoid EGL graded diamonds.


The Process of Grading a Diamond is Stringent
If you buy a diamond certified from one of the two certifying agencies above, you can rest assured that the diamond has been through a very rigorous examination. The diamond is measured and weighed, as well as being closely examined using equipment that allows the examiner to see deeply into the diamond to evaluate color and clarity.
One thing the examiner does not do is assign your diamond a value. The current market in part determines diamond values, so these can fluctuate. For the value of your diamond, you need an appraisal, which is a totally separate process.
The Fifth C of Diamonds – Certification Ensures a Good Purchase
By choosing a certified diamond, you ensure that your diamond investment is sound. A certified diamond is guaranteed to be the weight, color, clarity and cut stated. A certified diamond is also marked for identification. You can register your diamond after purchase by putting the certification number in your name. This can help recover the diamond if it is ever lost or stolen.
Not every diamond you see in a store will have the fifth “C” of diamonds. Certification is not performed on every diamond sold in America. However, most reputable jewelers will carry some certified diamonds. Be certain to ask for this certification if you want to ensure the very best diamond purchase.