Or if you really don't believe it, you can go to the jewelry counters in other large shopping malls and ask the sales staff to test you with a drill pen (jewelry counters generally have it) or ask an experienced sales staff to help you identify it (not everyone knows it). Or go to the local testing agency for testing.
In fact, don't worry, people just have a name to open a shop and sell jewelry. There is no problem with a formal business license. Never mind the discount, it's all a promotion.
The quality of diamonds is still quite good. Yue Leng is a person who doesn't understand jewelry. Don't let him mislead you. Even the smallest diamond will be certified. As long as it is a real diamond, by the way, in fact, the quality is unqualified, and the testing agency will not issue a certificate. The diamond ring previously tested by our factory has been returned because the gold has not reached the purity and other reasons.