GIA is the most authoritative jewelry appraisal institution in the world, and has conducted in-depth research on the discoloration synthesis of diamonds. Diamonds with GIA certificate can ensure that the origin of diamonds is natural and the origin of colors is natural.

Notarization is beyond doubt, including the classification standard of diamond appraisal formulated by GIA, which has the first professional diamond appraisal website in the world, and every diamond after 2000 can be queried online. Diamonds of the same grade and GIA certificate are the most expensive. Basically, it can be approved by 95% of domestic appraisal institutions.

The classification of demarcation point evaluation is very fine and the most rigorous. The clarity of the grasp is also in place. Almost every diamond's waistline is engraved with H & GIA certificate number, and perfect diamonds with eight hearts and eight arrows are engraved with H&'s logo.

Second, HRD of Belgian Diamond High Council.

As a diamond identification laboratory, HRD is at the forefront of the research on diamond processing and testing technology and equipment in the world. HRD certificate not only describes the common 4C characteristics of diamonds, but also makes a detailed measurement report on the cut ratio, which is recorded in the certificate.

The biggest difference between them is that HRD divides the percentage of the total depth of diamonds into three items: girth (Grde), crown height (crown height) and pavilion depth (pavilion depth). HRD certificate is more popular in Europe.

Three. IGI in the laboratory of Belgium Gemological Institute

The low requirements for color control have exploited loopholes for many diamond dealers. Like GIA, the cut-off rating of IGI certificate is still valid. Basically, 65% can pass the approval of domestic appraisal institutions.

Four. EGL in the laboratory of European Gemological Institute

EGL certificate has a more accurate grasp of clarity and cut, but it is too common that diamonds with the color I or even J are classified as H or G and then sold to greedy customers at a lower price. Basically, 55% can pass the approval of domestic appraisal institutions.

EGL If the color on the certificate is H color, it may be I color according to GIA standard, and the definition of VVS2 may be VS 1 or VS2. Therefore, the price of diamonds with EGL certificate is much cheaper than that with GIA certificate, sometimes half as cheap.

If you have a collection of diamonds with GIA certificates, you'd better buy them!

For these four kinds of diamonds, it is recommended to buy diamonds with GIA certificate. After all, the credibility of GIA certificate has been internationally recognized, which not only effectively guarantees the quality of diamonds, but also proves that it can be recognized globally.