Give you a popular science. At present, there are two common ways to forge certificates: the first one: the certificate is fake and the diamond is fake! (Common fake diamonds include zircon and kyanite. ); The second type: the certificate is real and the diamond is fake, that is, the certificate is set and the certificate does not match the diamond. Almost all diamonds identified by IGI have laser anti-counterfeiting, that is, the number corresponding to the diamond identified by IGI is engraved on the waist of the diamond by laser. Almost all IGI diamonds have their own separate numbers, which are exactly the same as those on the matching certificates, just like the ID number. Another trick is that high-end jewelry stores will be equipped with laboratory microscopes to ensure that the IGI code and certificate correspond completely. If you are really worried, you can go to the laboratory for re-examination. IGI has branches in Shanghai and Shenzhen.