Through the sign on the certificate, it can be confirmed that the testing institution that issued the certificate has passed these special qualifications. The sign that appears on the general certificate is "CMA"
"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.
Step 2: 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 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.
Step 3: Test the content (the most important content).
This step should be the content of the exam that we are most concerned about, and we should know which content on the certificate is the most important.
Grading certificate of inlaid diamonds: the most important thing to pay attention to is the color grade and clarity grade of diamonds, and some certificates also have the cut ratio of diamonds.
Purity inspection certificate of precious metal ornaments: the most important thing is of course the type and content of precious metals.
Jewelry and jade appraisal certificate: the inspection conclusion is the most important. 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.
"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 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.