Among them, GIA and HRD, namely American Gemological Institute and Belgian Gemological Association, have formulated the strictest and most authoritative diamond grading standards. Holders of carat diamonds with the above two certificates can easily obtain mortgage loans from banks in developed countries. At present, in China, more consumers choose GIA's diamond appraisal certificate, which has become the mainstream of the domestic diamond market. The GIA diamond identification certificate of various carats not only indicates the characteristics such as weight, size and fluorescence reaction, but also stipulates the grading standards such as clarity and fineness. Among them, the color scale is marked with English letters, from the highest color scale D to the lowest color scale Z, and the color is from white to yellow, with a total of 32 levels * * *; Clarity is divided into IF, VVS 1, VVS2, VS 1, VS2, SI 1, SI2, SI3, P 1, P2, P3 and other * *1grade standards. The seemingly boring figures on the diamond appraisal certificate are actually closely related to the pockets of every consumer. For example, a 1 carat diamond has good color, clarity and cutting. Compared with a 1 carat diamond with poor color, clarity and cut, the price difference may be 70% to 80%. According to the current domestic price, the difference between the two may be as high as tens of thousands of yuan. Many consumers are very concerned about the color of diamonds and always want to choose D color. In fact, chromaticity, as a very important indicator of diamonds, has a very critical impact on the price of diamonds. The chromaticity change of each grade may affect the diamond price by 20%-30%. For consumers, it is almost impossible to tell the difference between D color and H color with naked eyes, so Ivan suggested that in the case of limited budget, proper consideration of reasonable chromaticity may save you a lot of money. Among the 4Cs of diamonds, only cutting is affected by human factors, so the pursuit of perfect cutting has become the pursuit of another part of consumers. Similarly, according to GIA's certificate, the nominal perfect cut (EX) is five grades short, and each grade may affect the diamond price by 30%-40%. But for the naked eye, the EX and VG of diamond cutting can't be clearly distinguished, so choosing the right diamond cutting will also save you a lot of money.