It is not recommended that you buy diamonds according to the 4C standard of diamonds: the size, color, purity and cut purity represent the "purity" of diamonds, and the purity is evaluated according to the number, type, location and size of inclusions. When buying a diamond, you need to consider the inclusion, because the purity of the diamond itself is affected by the purity of the diamond. GIA uses a magnifying glass of 10 to classify diamonds when testing them. Clarity grading standard FL: observed under a magnifying glass of ten times, the diamond is clean, that is, there are no inclusions inside and outside the diamond, which is a very rare grade. If: under the magnifying glass of ten times, there is no flaw inside, and there may be a little flaw on the surface, but it can be removed by polishing again, which is very rare. VVS 1-VVS2: The internal and external features are very small, so it is extremely difficult to observe under a ten-fold magnifying glass, and the cleanliness is very good. VS 1-VS2: Fine internal and external features, tiny inclusions invisible to the naked eye, difficult to observe under a magnifying glass of ten times, with good clarity. SI 1-SI2: It has obvious internal and external characteristics, small inclusions visible to the naked eye and low purity. I 1-I3: Visible inclusions with low clarity. The most important item of clarity is its influence on diamond quality. Many people think that diamonds are the hardest. How can there be quality problems? This is a big misunderstanding. Although diamonds are the hardest, they are also brittle. If there are too many inclusions and too much external force, the diamond may crack. Just like a complete piece of paper, it is difficult to tear, but it is the same reason to poke two or three small holes in the middle and then break it. There are too many internal defects in hard things, which will have a great impact. Many people think that as long as there is something wrong with the diamond, they should buy fake diamonds, and seldom consider the relationship between the clarity of the diamond itself, because if a diamond with too low clarity has a feather crack (but too low clarity is called a feather crack), it may extend to the outside of the diamond, but it is difficult for buyers to see whether the defect is inside or outside. If they buy diamonds with such clarity, inlay or external force will aggravate the cracks, so the diamonds will not break, but there will be. In addition, international brands do not sell diamonds below VS, such as Cartier, Tiffany, Dior and Chanel. I'm glad to answer the landlord's question. Please forgive me if there is any mistake.