In the classification standard, P grade refers to the gem-grade diamond with the lowest clarity grade, and diamonds below P grade are generally not regarded as gem-grade diamonds. When buying diamonds, it is generally not recommended to buy P-grade diamonds. These diamonds have defects visible to the naked eye, which will greatly reduce the visual effect of diamonds.

Basic information:

Its greatest feature is the systematization of theoretical knowledge and the practicability of operation methods. It can be used as the corresponding teaching material for gem specialty in colleges and universities, and it is also an important reference book for diamond processing, identification, grading, commerce and other practitioners, which is more suitable for jewelry lovers to collect and read. Years of diamond work experience and teaching experience, taking the national diamond grading standards as the program, widely referring to the major international diamond grading standards.

Combined with the latest diamond research results and market information. The author insists on integrating theory with practice, and systematically introduces the basic gemological properties of diamonds, the basic concepts of diamond 4C classification, the working methods and requirements of diamond 4C classification, the synthesis and optimization of diamonds, the discrimination between diamonds and imitation diamonds, and the trade and market of diamonds.

Diamond clarity classification * * * is divided into five grades: LC (flawless grade), VVS (extremely flawed grade), VS (flawed grade), SI (tiny flawed grade) and P (flawed grade). On this basis, according to the size, quantity, location and nature of the clarity characteristics, it is subdivided into eleven small levels (FL, IF, VVS 1, VVS2, SI 1, SI2, P 1, P2 and P3) (P level corresponds to I level in GIA classification).