At present, the most authoritative jewelry appraisal certificate in China is CGC (National Jewelry and Jade Quality Inspector) of NGTC. There is no exam every two years, and now the registration is closed. Submit it next time ~ the tuition is very expensive and the pass rate is extremely low! Most of the graduate students of Jewelry College of China Geo University died before.

You can also take the GIA diamond grading certificate of the United States, which is universal. The registration fee seems to be 18 thousand. 4C is not very difficult, but they are very strict in the exam. If you do something wrong in the experiment, just make up the exam directly ~

And the FGA in Britain, which is about colored gems, has added a lot of money. I suggest you learn the basics first, and then try, which is safer and does not waste money.