1, institutional qualification

There are four kinds of institutional qualification certification: CAL certification, CMA certification, CNAS certification and ILAC-MRA certification. CMA is a compulsory certification of appraisal institutions by the state, which must be possessed. Others are voluntary, but generally large testing institutions will have these signs at the same time.

2. Contact information

On the reverse side of the certificate, in addition to the qualification of the institution, there must also be information such as the name, contact number, address and website of the appraisal institution.

Step 3 check the signature

The certificate needs to have the name of the inspector and the name of the reviewer (approver), and neither signature can be less.

Step 4 identify the content

Different certificates have different emphases, but the more detailed the examination content, the better. The jewelry you choose should be consistent with the sample described in the certificate. Diamond grading certificate, 4C grade; The purity inspection certificate of precious metal jewelry shall contain the types and contents of precious metals; Jewelry and jade appraisal certificates must have accurate inspection conclusions.

5, the national standard number

Jewelry testing in China follows national standards. GB/T

16552 name of jewelry and jade; GB/T 16553 jewelry and jade identification; GB/T 16554 diamond classification; GB/T

18043 nondestructive testing method of precious metal jewelry content: x-ray fluorescence spectrometry; gbyte

1 1887 Rules and naming methods for the purity of precious metals in jewelry. Those without T are mandatory standards, and those with T are recommended standards.

6. Identification of steel seal

Each independent appraisal institution has the official seal of the department, and the appraisal certificate must be stamped with the official seal of the unit, and the content of the steel seal is used as a mark to test the authenticity of the certificate. The full name of the issuing agency must be printed on the steel seal, and individual agencies will also have department codes.

7. Other information

Each appraisal certificate has an independent and non-repetitive number, which is the certificate number of the certificate. Various institutions have also taken many anti-counterfeiting measures for their own rights and interests, such as NGTC anti-counterfeiting code, laser anti-counterfeiting label, marking fluorescence under ultraviolet light and so on.