For a finished diamond, usually, it is evaluated from four standards within the related industry, namely the color, the carat, the clarity and the cut. As the relevant English words of the four standards start with the same letter “C”, they are called 4C customarily.

In the corlor evaluation, only the cape series diamonds are supposed to be classified when their corlor is qualified, from colorlessness to buff.At present, the CIBJO and the GIA are the main two references, namely using the English letters from D to Z to divide into twenty-three different grades. In this case, the former the letter is, the higher the diamond’s color grade is.

Next is the clarity. According to the standard, the clarity of the diamond can be divided into five grades. The best one is LC, which means there is not any blemishes on the diamond, then the VVS, containing atomic blemishes, divided into two branch, namely VVS1 and VVS2. The following is VS, with tiny blemishes, also divided into VS1 and VS2. Next two are SI and P, separately owning a few and many blemishes.

The cut is the only part in the 4C that can be directly handled by people. To a great extent, the cut will affect the fire and brightness of the diamond, as well as the price. In the cut grades, nothing but the polygon shape of cut round diamonds are involved strictly. In the China’s national standards, the crown height, the waist depth, the pavilion depth, the desk width, the total depth and the degree of modification of the diamond are usually evaluated into five grades, including Excellent, Very Good, Good, Fair and Poor.

The last one is the carat. Universally, the weight of the diamond is signified with Ct, and usually, 1 Ct is equal to 100 grades or 0.5 Gram. The price of the diamond is directly related with its weight, that is to say the diamond with heavier weight is more expensive when any other factors are the same. What’s more, the rise of the price is not according to the arithmetic progression.

Actually, each factors of the 4C is important. All of them will make a big difference to the final price of the diamond. Of course, as we all know, the weight is the key.