Let’s first look at what certification really is.
What Are Certified Diamonds?
Certified diamonds are stones that have been formally appraised and whose quality characteristics have been documented.
Such diamonds come with a grading report, which is the document describing their clarity, cut, color, carat weight, and other important features.
Who Certifies Diamonds?
Diamonds are certified by independent experts, who are trained in gemology. One of the most respected certification authorities is the G.I.A. (Gemological Institute of America).
You should remember that certification makes sense to you as a buyer only if it is done by a third party that is not connected with the jeweler selling you the diamond. After all, if the seller can influence how his or her merchandise is evaluated, the quality assessment may be biased, and that’s not what you want.
Why Some Diamonds Do Not Have a Certificate
Many diamonds are not certified for a variety of reasons.
Certification costs money, and some merchants don’t want to incur additional expenses.
Sometimes, jewelers think it’s not worth it to have low-quality diamonds certified because for such stones, a certificate would not make a big difference to the buyer.
And there are also sellers who prefer to offer non-certified stones so that they can present the quality of these diamonds in the best possible light.
So What If a Diamond Is Not Certified?
Certification matters to you as a buyer because it provides an independent verification of a diamond’s quality.
Without a certificate, you can never be certain what you are buying. If a diamond is not certified, your only source of information about its quality is the seller, and needless to say, the merchant’s assessment is not likely to be the most objective.
If the seller exaggerates the quality of an uncertified diamond, you may end up overpaying for a stone that would be put in a lower price range if it were certified.
A Note: Diamond Quality Is Not Set in Stone
Although diamond grading labs follow robust guidelines when evaluating diamonds, the exact grade on any given characteristic ultimately comes down to the opinion of the expert making the assessment.
Laboratories try to make the process as accurate as possible by requiring that each stone be assessed by multiple graders.
However, due to the inherent subjectivity of diamond grading, merchants are allowed to have some leeway when representing a diamond’s quality to the customer. They are allowed to increase the color and clarity grades of a stone, but by no more than one grade up from what the diamond would be graded by an independent appraiser.
So, you should keep in mind that if you are buying an uncertified diamond, the jeweler may be giving you an optimistic assessment of its quality and this can be perfectly legal.
The Bottom Line
If you want to make sure that the quality of the diamond you buy is what the jeweler claims it to be, always ask for a certificate, and don’t buy uncertified stones.
If the diamond doesn’t come with a grading report, there is no way of knowing what the stone’s exact quality is.
Differences between adjacent color grades, for example, can be so subtle as to be invisible to the naked eye.
However, they could make a big difference to your wallet, especially if you buy an uncertified diamond that has its color bumped up by one grade.For more information on diamonds: Read our Diamond Cut Quality Guide.
Important: We recommend that you only buy diamonds that you have seen and examined in detail. Each diamond is unique, and a mere description of color, cut and clarity is not sufficient, as even stones of the same grades might look different.