They are all fake, and the quality is the worst. It's just a consumption trap. The salesman will say that jewelry has a certificate and the certificate is made of money. He'll say it has a steel seal. It's all fake. The salesman will also say that there is a website to enter the license number, and the website is made of money. If you can't stand the temptation to buy it, you don't need to open an appraisal certificate. You can get a refund from the Consumer Association and the Industrial and Commercial Bureau. Your tone must be firm.