The authenticity and quality of diamonds actually have little to do with the company. The key to your question should be to question this diamond.

I don't know how big the diamond you bought is. Generally, when selling diamonds, a certificate will be issued. However, if the diamond is less than 20 cents, the state will not force a certificate when selling it.

Generally speaking, diamond grading is a term for broken diamonds, because large diamonds are marked with 4C parameters in detail, rather than simple grading. But the content of the grading card should be the same as that of the certificate, indicating the weight, cleanliness, chromaticity and cutting work. Of course, it may not be complete, but the basic weight, cleanliness and chromaticity should be available.

If the grading card given to you by the merchant is not the appraisal certificate of an authoritative organization, it can't be said that it must be fake, but it can't be guaranteed. If the score exceeds 20, go back and ask him to make up a certificate. If you are not at ease, you can only re-examine and keep the invoice in case there is any problem with the appraisal result.

To see if the certificate is authoritative, you can look at the mark on it.

The authoritative appraisal certificate shall be marked with the words "CMA", "CAL" and "CNAL". There must be at least one of the three signs, and all three signs indicate that the appraisal institution has the highest ability and level.

CMA-the basic requirement of national laws for testing and inspection institutions, and the institutions with this mark are statutory inspection institutions;

CAL- is the symbol of the inspection organization recognized by the national quality inspection. Institutions with this mark are qualified to make arbitration inspection conclusions. Compared with the mechanism with CMA only, the mechanism with CAL has better quality and reliability.

Cnal-the symbol of national laboratory. According to the relevant agreements of China's accession to the WTO, the "CNAL" logo can be recognized internationally, such as the United States, Japan, France, Germany, Britain and other countries.