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, 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.
A customer who was trying to decide between several diamonds. Her husband wanted to buy her the stone with the best report, but she preferred another stone which, according to what was on the reports, wasn’t as good. They decide against the best diamond and bought the one that made her happiest. The important thing is that they knew exactly what they were buying, and paid an appropriate price for that specific combination of quality factors. In other words, they made an informed choice. The reports gave them assurance as to the facts, and greater confidence that they knew what they were really comparing.
Improper use of reports can lead to costly mistakes
As important s diamond grading reports can be, they can also be misused and lead to erroneous conclusions and costly mistakes. The key to being able to rely on a diamond report, and having confidence in your decision, lies in knowing how to read it properly. For example, when trying to decide between two 對戒 diamonds accompanied by diamond grading reports, buyers all too often make a decision by comparing just two factors evaluated on the reports, color and clarity, and think they have made a sound decision. This is rarely the case. No one can make a sound decision based on color and clarity alone. In fact, when significant price differences exists between two stones of the same color and clarity as the more expensive stone, and often it is not the better value. Having the same color and clarity is only part of the total picture. Differences in price indicates differences in quality, differences you may not see or understand. With round diamonds, the information you need is on the report, but you need to understand what all the information means before you can make valid comparisons.