1. Look at the certificate sign: When buying jewelry, don't trust the merchant's verbal promise, but ask the merchant for an authoritative jewelry appraisal certificate. The issuing institution of jewelry appraisal certificate must be certified by the state. There are three forms of qualification certification of jewelry appraisal certificate institutions: CMA measurement certification, CAL authorization certification and CNAS laboratory certification. Among them, CMA certification is the measurement certification of appraisal institutions by the state according to the measurement law, and it is necessary in all jewelry appraisal certificates. Only institutions that have been certified by metrology can release certificate data to the outside world. To confirm its authenticity, you can check with the complaint department of the national or local quality inspection agency.
2. Look at the test content: the test content includes the name of the jewelry, the quality grade, shape, color, cleanliness and total quality of the gem. Check the physical product against the physical picture on the certificate. The inspection certificate is a one-to-one correspondence with the product, and it is the only appraisal document for each product, including: the photo of the sample, the weight on the label and the weight on the certificate, and whether the appearance and description of the jewelry are one-to-one correspondence.
3. Inspection conclusion: According to the national standard, the word "natural" is no longer marked on natural jewelry and jade, but the artificially processed or artificially synthesized gems must be clearly marked. For example, the conclusion is "ruby", which means that this ruby is pure natural; "Ruby (treatment)" means a specific treatment method, which means that this ruby is a natural gem, but its appearance has been improved by some artificial treatment.
4. Look at the official seal or inspection mark: the formal quality inspection certificate of jewelry and jade must be signed by two people, one of whom must be a Chinese quality inspector (registered) and registered within the validity period, so that the inspection certificate can have legal effect. In order to prevent the certificate of appraisal institution from being forged, the appraisal certificate must be stamped with the official seal of the unit, and the red official seal as the inspection mark is often not printed with the certificate, but stamped after inspection.
5. National standards: The general appraisal certificate will also indicate the basic standards for jewelry and jade appraisal. The current national standards specifically include: GB/T 16552 Names 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; GB 1 1887 Rules and naming methods for the purity of precious metals in jewelry.
This is the introduction of how to distinguish the authenticity of jewelry appraisal certificate.