Not necessarily. You can identify jadeites a, b and c by yourself. Tips: Observe the lighting to see if there is a faint yellow tone. If there is, it is basically determined as A, and if there is no light color, it can be basically determined as B or B+C (except for the green species with white background, the glue of B goods will turn yellow after a long time).
Normal! The refractive index is one of the characteristics to determine that the detected object is natural jadeite, which is generally 66. However, there are many testing items to determine natural A jadeite, and major testing institutions make comprehensive judgments according to their respective testing habits. No refractive index does not mean abnormal.
Jade bracelet, there is no data such as refractive index, spectral analysis, density and refractive index on the certificate. , but only marked a goods, which are largely natural jade a goods! This kind of certificate, called batch certificate, is generally a large jewelry company, and a large number of goods are uniformly appraised by jewelry and jade appraisal institutions, and certificates are issued.
Wait a minute. Certificates should be in one-to-one correspondence, that is, a thing is a certificate, and the certificate should have pictures and weights of the goods. Although some things come from a piece of raw material and look similar in appearance, jade ornaments are not exactly the same. One thing with a certificate can't prove the quality of the whole batch of things.
In addition, all provinces in China have corresponding provincial jewelry appraisal centers, which can also issue jade inspection certificates. Finally, some third-party organizations can also issue appraisal certificates, but these certificates are naturally not as effective as NGTC.