Generally speaking, when buying jewelry, you may not be credible if you have a certificate, and you may not be credible if you don't have a certificate. Except for the composition problem that is difficult to prove.

If you look at the certificate, GIA/ GRS/AIGS are all international authoritative appraisal certificates, or you can look for domestic certificate appraisal institutions, which can be found online. The standards for detecting the authenticity of certificates include: clear identification of certificates, consistent appearance description, comprehensive detection contents, official seal, etc.