Certification, Reports, and Appraisals: The Business of Selling Confidence
Certificates of Authenticity: What They Are—and What They Are Not
Recently, a customer asked if I could provide a certificate of authenticity (COA) for the diamond in a ring he had purchased as a gift. His request was understandable—he wanted to offer reassurance to the recipient that the piece was genuine.
Many people are conditioned to feel confident when a purchase is accompanied by a COA. In reality, certificates of authenticity are rarely necessary in fine jewelry unless the piece is a limited edition or from a specific designer. While COAs can offer peace of mind, they can also be misleading.
When COAs Create Misleading Confidence
Example 1: The “Diamond” That Wasn’t
A gentleman once brought me a ring he had purchased at auction for his wife. The word “diamond” appeared in the listing title, but upon examination, I immediately noticed telltale signs that the stones were not diamonds: a different luster, rounded facet junctions, and colloidal fractions. At the time, I was still completing my education at GIA.
The couple trusted the COA they had received and believed it to be definitive. I encouraged them to have the stone tested at any jewelry store using a thermal diamond tester. When his wife later read the COA aloud to me, it stated: “[Brand] created diamond” and “fine stimulant.”
This language was intentionally misleading. I had to explain that a diamond stimulant is not a diamond at all—it was a branded cubic zirconia. The COA served only as marketing material designed to make the purchase feel special, not to provide true gemological clarity.
Example 2: The “Emerald” Illusion
In another case, a jewelry store owner showed me a large emerald he had recently purchased. Immediately, I suspected something was off. He confidently produced a COA describing the stone as emerald.
While the report stated the gem was beryl (the mineral family to which emeralds belong), it also disclosed that the stone was dyed and assembled as a triplet. The owner did not understand what this meant.
If the stone were indeed beryl (colorless beryl is known as goshenite), it had been cut, then bonded with adhesive, and dyed green to simulate an emerald. When tested on the table (top) of the stone, it could register as emerald—giving the illusion of authenticity. He believed he had acquired a large natural emerald at a bargain, when in fact, it was a constructed stone.
The Role of FTC Regulations
In the United States, jewelry sellers are bound by Federal Trade Commission (FTC) regulations. We are legally required to accurately describe what we are selling. That written description—paired with the price paid—can serve as legal certification.
In the case of my customer’s diamond ring, the stone was modest in size and price. The cost to unmount the diamond, submit it to GIA, and reset it would have exceeded the price of the ring itself. Providing a COA stating the diamond was natural would have been redundant—it would merely have restated the information already disclosed in the item description. Essentially it is a nice touch to the presentation, but not a superior means of an authentication statement.
How to Get Assurance Without a COA
If you want to confirm that a diamond is “real” and do not fully trust the seller, almost any jewelry store or pawn shop will test it for free. They can tell you whether it is a diamond, but they are less likely to determine whether it is natural or lab-grown--especially if the diamond is of more modest size.
That distinction requires additional training and specialized equipment. Since lab-grown diamonds also contain inclusions, differentiating them from natural diamonds can be challenging without proper gemological education, tools, or a reputable lab report.
If you are purchasing from a GIA Gemologist or Graduate Gemologist, you can generally be confident that the information provided is accurate to the best of their knowledge and training.
Always keep your original receipt and item description. These documents serve not only as your best declaration of authentication, but also as a form of appraisal. If an item cannot be replaced at the same value and insurance documentation is needed, a formal appraisal may be appropriate.
Final Thoughts
Certificates of authenticity are often used as marketing tools rather than clear guarantees. I encourage consumers to be cautious—especially when a COA is from overseas, misleading, or conflicts with the actual description of the item.