No matter how clever the anti-counterfeiting technology is, as long as it can prevent counterfeiting, it is possible to be counterfeited. Counterfeiters pursue huge profits, either by replacing them with imitation diamonds or by using diamonds with grades lower than those marked by GIA certificates. Either way, its quality is definitely far from the quality indicated on the GIA certificate. However, domestic re-inspection can at least prove that the quality of diamonds is consistent with that indicated in the GIA certificate, thus making counterfeiters unprofitable and avoiding the possibility of buying diamonds with fake GIA certificates.

Although the quality grading standards of diamonds are very detailed, the gap between adjacent grades is often difficult for non-professionals to distinguish. But these levels are still ranges, not absolute values. Since it is an interval, there is a critical point. For example, G color and H color are two adjacent grades, but the difference between the worse diamonds in G color and the better diamonds in H color is extremely weak. Similarly, for example, the actual difference between poor quality VS2 diamonds and good quality SI 1 diamonds is also very weak.