Today, few fine diamonds over one carat are sold without a diamond grading report, or certificate, as they are also called, from a respected laboratory. Reports issued by the GIA/Gem trade laboratory are most widely used in the United States and many countries around world.
A grading report does more than clarify the stone’s genuineness, it fully describes the stone and evaluate each of the critical factors affecting quality, beauty, and value. Grading reports can be very useful for a variety of reasons. The information they contain can provide verification of the “facts” as represented by the seller and enable one to make a safer decision when purchasing a diamond. Another, important function of reports is to verify the identity of a specific diamond at some future time, if, for example, it has been out of one’s possession for any reason. For insurance purposes, the information provided on the report will help ensure replacement of a lost or stolen diamond with one that is truly “compatible quality.”
Reports are not necessary for every diamond, and many beautiful diamonds used in jewelry are sold without them. But when considering the purchase of a very fine diamond weighting one carat or more, we strongly recommend that the diamond be accompanied by a report, even if it means having a diamond removed from its setting (no reputable lab will issue a report on a mounted diamond), and then reset. If you are considering a diamond that lacks a report, it is easy for your jeweler to obtain one. Or, now that GIA is issuing diamond grading reports to the public 鑽石戒指款式 , you may submit a diamond at GIA yourself.
Do not rely on the report alone
The availability and widespread use of diamond grading reports can, when properly understood, enable even those without professional skills to make valid comparisons between several stones, and thus make more informed buying decisions. Reports can be an important tool to help you understand differences affecting price. But we must caution you not to let them interfere with what you like or really want. Remember, some diamonds are very beautiful even though they don’t adhere to establish standards. In the final analysis, use your own eyes and ask yourself how you like the stone.