95% of my friends don't know how to calculate the price of diamonds, so I'll teach you a method: the diamond appraisal certificate has both diameter and height. For example, you see in the appraisal book that the clarity of your diamond is VS 1, the color is H, the weight is 1 carat, and the diameter is 6.22-6.25mm Your calculation formula is: the cubic of the diameter times 0.00366. Example: 6.22 X 6.22 X 6.22 X 0.00366 = 0.8807 That is to say, your 1 carat diamond is actually a 0.88-carat diamond, which is a hard-working diamond with a weight guarantee of 1 carat! If you buy 1 carat diamonds, you will lose a lot. The error of calculation results is preferably between 0.03 and 0.04 mm, which is one of the best diamond tools. 1 is the composition of the retail price of loose diamonds. In a more formal jewelry store, the retail price of diamonds is generally composed as follows: the cost price of diamonds x17% (value-added tax) X 5%% (high consumption tax) X 10-30%-30% (counter rent) x 3-5% (promotion fee) x 3% (advertising fee) x 30. Diamonds with perfect cutting, eight hearts and eight arrows and very standard diameter and height only account for about 15% of all diamonds. Therefore, it is necessary to add 15% to cut the perfect diamond. Why is it so expensive to cut a perfect diamond? For example: 1 carat rough diamond, and perfect cutting needs 4-5 carats rough diamond to complete; Similarly, the rough stone of 1 carat only needs about 2 carats to cut. Now you understand: the purchase cost of 2-carat rough diamonds and 4-5-carat rough diamonds is the geometric base, and diamonds are sold very cheaply, even surprisingly cheaply. 100% is fishy. Perfect cut diamonds, if the price is very cheap, are being bought everywhere, why should they be sold to you below the purchase price? So far, my friends and I, as well as friends from foreign diamond dealers, have no problem in not seeing a "very cheap" diamond. Of course, this case does not include theft and robbery. Reference answer: weight (ct) quality description City God jewelry sales price (RMB) 0.30 d vvs29 29,080 0.50 D VVS128,420 0.70 F VVS 232,3801.00 D VVS 21.