The certificate of Guangdong Gold, Silver and Jewelry Testing Center is issued by a national inspection institution with appraisal qualification, and the most authoritative one in Guangdong Province is Guangdong Gold, Silver and Jewelry Testing Center, so the possibility of fraud is very small. Professional jewelry appraisal certificate is a public proof of the authenticity and attributes of precious metals and gemstone finished materials designated by professional institutions and professionals who meet the national appraisal standards. In China, the state has strict qualification requirements for jewelry and jade quality appraisal institutions, and only through accreditation can the appraisal certificate have legal effect.