IGI's certificate is issued by the international gemological institute with certain authority in the world. There are IGI training and education institutions and regular examinations in Shanghai. The cost is ok, about 20 thousand to 30 thousand, and it lasts for a long time. There are still many practical opportunities in the IGI diamond appraisal course. It's no use learning gem identification. IGI will have a half-day evaluation practice time. If you want to study jewelry appraisal systematically, you can go to IGI.