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The 4 standards of judging the the quality of diamonds.

  • Author:Fiona
  • Source:Lee
  • Release on:2017-06-21
"4C" is a measure of the value and quality of a diamond. The so-called "4C" is the abbreviation of four English words beginning with C, referring to the CARAT WEIGHT, CLARITY, COLOR, and CUT. Just a "4C" four points to appreciate, you can easily understand the value and quality of a diamond. Diamond Price = Weight Color Clarity Cut. Diamond 4C important proportions are: weight 40%, color, clarity, cut the 20%.

Carat weight (Carat)

Diamond weight to carat (also known as card) calculation. 1 carat = 200 mg = 0.2 g. One carat is divided into one hundred copies, each one is called a point. 0.75 carat is also known as 75 points, 0.02 carat for 2 points. In the case of other conditions similar to the increase in the weight of the diamond, the value of the geometric progression of the growth; the same weight of diamonds, due to color, clarity, cut the different value and far. In each of the different sizes and shapes, can be found in high quality diamonds, the most important thing is to find a suitable size and let you like the diamonds. You may wish to try to see in the jewelry store, when it looks and feel right when the sinking on yours.


Diamond crystals in the depths of the earth mantle magma, the environment is complex, diverse, high temperature and pressure, after hundreds of millions of years of geological changes, the internal inevitably contain a variety of debris or flaws. The color, size, size, and location distribution of these inclusions have different degrees of effect on the clarity of the diamond.

Diamond clarity is usually 10 times magnifying glass on the diamond internal, surface defects and their impact on the glory of the degree of inlaid diamonds are graded, according to the standard of China's national inspection is divided into LC, VVS1, VVS2, VS1, VS2 , SI1, SI2, P1, P2, P3 a total of 10 levels. Inlaid diamonds are divided into excellent, good, good, good, generally 5 levels. P-class drill is also known as grade I drill P-class drill is generally not used as a gem drill, so generally only to the P-level, no longer P1 \ P2 \ P3.


Diamonds have a variety of natural colors, from the precious colorless (white after cutting), rare light blue, pink to the common yellowish range. The more transparent colorless, the more white can penetrate, after refraction and dispersion is more colorful.

Diamond color grading is in the professional laboratory grading environment, by the technical staff to be classified diamonds and standard color than the color stone and repeatedly determined.

The most white diamond is set to D (ie from Diamond's first letter). Diamond color is divided into 11 levels, followed by: D, E, F, G, H, I, J, K, L, M, N.

Cut (Cut)

The cut of the diamond refers to the accuracy of its cutting ratio and the completeness of the modification. Good cut should be as much as possible to reflect the brightness and fire color of diamonds, and try to keep the original stone weight. IGI International Gemological Institute of the cut from high to low is divided into ID (standard), EX (excellent), VG (good) G (good), China's national inspection is divided into: EX (excellent), VG (very good) , G (good)

In China, ordinary people generally look at the size of the weight to measure the value of diamonds. Actually unscientific. Because China is more popular small drill. Therefore, the more popular concept is high quality glory diamonds. High-quality glory of the diamond is generally grasp the three principles of 4C: Clarity (Clarity), color (Color), cut (Cut), and three standards to achieve a certain standard at the same time.