Teach you how to understand the jade identification certificate

First of all, the most important aspect of an identification certificate is the identification result. You should be clear that what we usually call “A, B, C, and D” is a saying that experts use to distinguish between natural jade and artificial jade. It does not mean that the quality of natural jade is good, medium, or bad. Actually, A cargo is a natural jadeite whose internal structure has not been artificially processed by anyone. B cargo is removed from the natural jadeite by strong acid. C cargo is artificially dyed by its color, and D cargo is impregnated with other jade or glass. Emerald. In fact, both B and C have destroyed their natural structure, but they will look beautiful, and wearing it for a long time will also bring about some negative effects on your body.

The Emerald certificate issued by the national authority is one of the identification results. If it is a natural A cargo jadeite, the result is only the word “Jade”, and the words “A cargo” and “natural” will not be marked. This is because only a natural A product will issue a certificate that results in "Jade", and if it is a B product, an identification result in the certificate will indicate "emerald (treatment)" or "emerald (gel injection)" or Emerald (B) or Emerald (Optimized). C cargo jade will be marked "emerald (dyed)." In the identification certificate results, D-item Jade will not appear "emerald", what substitutes will indicate the name of such substitutes, such as "artificial glass", "dyeing quartzite," "Saiyu," " Malay jade" and so on. Why does A cargo jade not indicate "A cargo" or "natural"? Because according to the national unified standards for jewellery appraisal, it is the natural emerald that is marked with jade, natural diamonds are marked with diamonds, and only the processed gems appear behind the explanation.

Second, the certificate should be a one-to-one correspondence, that is, a piece of a certificate, and the certificate should have a picture and weight of the item. Although some things come from a piece of raw material, the appearance looks very similar, but the jadeite jewelry is not exactly the same, a thing that does a certificate does not prove the quality of the entire batch. In order to save costs, some businesses only have one certificate as a sample. The goods and objects on the photo are also similar. This does not determine that the batch of goods they sell is natural. This does not comply with the state regulations.

Third, there should be some basic physical, chemical and optical characteristics of jadeite on the certificate. Refractive index: 1.66 (This is a unique refractive index of jade, which is different from that of other precious stones); Density: 3.33 (It is also a distinguishing feature of jade and other precious stones); Magnification test: Fiber intertwining structure (This is a unique structure of jadeite) Absorption spectrum: absorption line at 437 nm (absorption spectrum unique to jadeite); color filter inspection: no reaction (some stained jadeite turns red under color filter); lightness: aggregate (emerald is a micro mineral aggregate); fluorescence : None (some B products will have a fluorescent reaction after gel injection); Appearance characteristics: glass luster (some B products will show a waxy luster). Finally, there must be the signature of the inspectors, and the most important point is that the certificate should have stencil or anti-counterfeiting marks.

The two most authoritative bodies in Beijing are the National Gemstone Quality Supervision and Inspection Center of the local mining department and the Beijing Gaode Jewelry Appraisal Institute under the former Ministry of Foreign Trade and Economic Cooperation. It is necessary to remind you that there are many companies that issue certificates that are not state-authorized. Such certificates may be compromised in accuracy and authority. According to the Chinese Baoyu Stone Association's 2004 No. 001 document, sampling results across the country showed that at least 19 certification organizations issued certificates that deliberately raised the quality of diamonds, identified quartzite as jadeite, and some of them identified There are a large number of unqualified tests. These problems are not limited by the level of detection, but they are for the sake of certain people. This is more of a concern for consumers.