1. The contact information of this institution must be printed on the certificate. In addition to the qualifications of the institution, the back of the certificate must also have the name, contact number, address, website and other detailed information of the recognized institution. 2. The qualification of the institution must be printed on the certificate. There are five kinds of accreditation: University of California, CMA, CNAL, CNAS and ICLAMRA. Among them, the inspection report marked "CMA" can be used for product quality evaluation, results and judicial appraisal, and has legal effect. The logo only means that the institution is a unit that has passed the measurement certification review and is a necessary qualification for any unit that issues a jewelry appraisal certificate. The certificate must be signed by the inspector. 4. The appraisal content on the certificate is comprehensive and detailed. 5. The identification items on the certificate must be printed by the machine. The national appraisal certificate needs to be printed by machine, and the manual appraisal certificate has no reference value. If an appraisal certificate has the above five information, then the certificate is more authoritative.