The issuer must pass the qualification certification authorized by the state. The sign that appears on the general certificate is "CMA CAL CNAS", at least with CMA sign. These three marks represent the recognition of national metrology institutions and national laboratories respectively. To confirm its authenticity, you can check with the complaint department of the national or local quality inspection agency.
1."CMA" is the English abbreviation of China Metrology Certification. It is a comprehensive certification and evaluation of the testing ability and reliability of testing institutions by the metrological administrative department of the people's government at or above the provincial level according to the provisions of the People's Republic of China (PRC) Metrology Law and the National Metrology Law. This symbol only indicates that the organization 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 inspection report marked "CMA" can be used for product quality evaluation, results and judicial appraisal, and has legal effect.
2. "CAL" is the abbreviation of China Certified Laboratory, which is the symbol of examination, approval and authorization. It is an administrative examination and approval system implemented by the state for quality inspection institutions affiliated to quality and technical supervision departments at all levels and authorized national and provincial quality inspection centers and stations. The appraisal certificate with this logo has authority and legal effect.
Both "CMA" and "CAL" are marked with the certification number passed by the laboratory.
3. "CNAS" is the abbreviation of China National Accreditation Committee for Conformity Assessment and the national accreditation symbol of China Laboratory. The use of CNAS marks indicates that the laboratory has passed the relevant accreditation of China National Accreditation Committee for Conformity Assessment.
Second, test the content.
Including jewelry name, gem quality grade, shape, color, clarity, total quality and other items.
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.
Photos are the direct evidence to distinguish different jewels and jade, and the identification certificate photos are clear and accurate, which will greatly increase the difficulty of forgery. However, in some cases, because the jewelry styles are similar and the photo features are similar, it is difficult to distinguish them. In this case, the accurate weight is another valid data that can be verified. In addition to photos and weight, the appraisal certificate will also provide some distinctive appearance features, such as the sugar color of jade, the size of bracelet and so on.
Third, the test conclusion
According to the national standard, natural jewelry and jade are no longer marked with the word "natural", but must be marked with artificial processed or synthetic gems, such as: the conclusion is "ruby", which means that this ruby is pure natural; "Ruby (treatment)" means the specific treatment method, which means that this ruby is a natural gem, but its appearance has been improved by some artificial treatment; "Synthetic ruby" means that ruby is not naturally produced, but is purely synthesized by artificial laboratory.