We can confirm that the testing organization that issued the certificate has passed those special qualifications through the sign on the certificate. The sign that appears on a general certificate is "CMA".
"CMA" is the English abbreviation of China Metrology Certification. It is a new certification and evaluation of the testing ability and reliability of testing institutions by the metrological administrative departments at or above the provincial level according to the provisions of * * * and the national metrology law. This symbol only indicates that the organization is a unit that has passed the measurement certification review, and it 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.
Secondly: appearance description (look at the model and observe the sample)
The next step is to confirm whether the purchased jewelry and jade are consistent with the samples described in the certificate, including the photos of the samples, the weight on the label and the weight on the certificate, and whether the appearance and description of the jewelry correspond.
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 correct weight is another verifiable data. 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.
Step 3: Test the content.
This step should be our concern, and we should know what is written on the certificate.
Grading certificate of inlaid diamonds: pay attention to the color grade and clarity grade of diamonds, and some certificates also have the cut ratio of diamonds.
Purity inspection certificate of precious metal jewelry: of course, it is the type and content of precious metal.
Jewelry and jade appraisal certificate: inspection conclusion. According to the national standard, the word "ruby" is no longer marked on jewelry and jade, but the artificially processed or synthesized gems should be clearly marked. For example, the conclusion is "ruby", which means that this ruby is an output; "Ruby (treatment)" means the specific treatment method, which means that this ruby is a gem, but it has been artificially treated in some way for appearance; "Synthetic ruby" means that ruby is not produced, but is purely synthesized by artificial laboratory.
"Remarks" column: Generally, some relatively special samples will be encountered in the testing process, which will be explained in the remarks. For example, in the appraisal certificate of Hetian jade, once the surface treatment is involved, the specific treatment method will be indicated in the remarks.
Step 4: Official seal or inspection mark
In order to prevent the certificate of the appraisal institution from being forged, the appraisal certificate must be stamped with the official seal of the unit. As the inspection mark, the red official seal is often not printed with the certificate, but stamped after inspection.
Now some large authentication machines are carrying out heavy anti-counterfeiting. For example, Xinjiang Rock and Mineral Gem Quality Inspection Station added the function of online inquiry in the new certificate issued in 2007. When inquiring, you need to enter the batch verification code and enterprise verification code, which is convenient for consumers to verify and understand the relevant information of jewelry and jade purchased online. "