The so-called "4C" is the abbreviation of four English words beginning with C, which refers to the weight, clarity, color and cut of diamonds. Combining the four points of "4C", we can easily understand the value and quality of a diamond. From the perspective of cost performance, the selection of loose diamonds must be focused. After the size is determined, it is recommended to consider cutting first. The quality of cutting directly affects the fire color of diamonds, so it is often said that cutting is the second life of diamonds. Secondly, considering the color, the closer to D-Z, the more penetrating the color, and the richer the color after refraction and dispersion. It is suggested that the final consideration should be cleanliness, preferably above VS level, because the influence of cleanliness on diamonds is only very small. As long as the clarity is perfect to the naked eye, it will not affect the beauty of diamonds. The weight in 4C is the most important factor affecting the basic price of diamonds, and it is also the world standard. This is the carat weight. The bigger the rarer, the better the quality.

weight

Weight (Carata), calculated in carats. 1 carat = 200mg = 0.2g A carat is divided into one hundred parts, and each part is called one point. 0.75 carat is also called 75 cents, and 0.02 carat is 2 cents.

(The word "carat" comes from the Greek word "keration", which refers to the carobseed, a plant widely spread from East Asia to the Middle East. Because its fruit is said to have almost the same weight, and the weight of diamond is the most easily measured feature in 4c, the early carob tree was used as the weight unit of jewelry and precious metals. One carat is equivalent to the weight of a small horn tree seed. )

clean

Cleanliness: Diamonds are crystallized from mantle magma deep in the earth, with complex environment, diverse components and extremely high temperature and pressure. After hundreds of millions of years of geological changes, it is inevitable that there are all kinds of sundries or defects in it. The color, quantity, size and location distribution of these inclusions have different degrees of influence on the clarity of diamonds. The clarity of a diamond is usually classified by using a magnifying glass with a magnification of 10 to classify the internal and surface defects of the diamond and their influence on the luster. According to the national inspection standard of China, it is subdivided into LC, VVS 1, VVS2, VS 1, VS2, SI 1, SI2, P 1 and P2. Diamonds are divided into five grades: excellent, very good, good and relatively good. P-class drill is also called I-class drill. Diamonds below grade P are generally not used as gems, so they are generally only classified as grade P, and are no longer classified as P 1\P2\P3.

colour

Color: Diamonds have many natural colors, ranging from precious colorless (white after cutting), rare light blue and pink to common light yellow. The more transparent and colorless, the more white can penetrate, and the richer the color after refraction and dispersion. The whitest diamond is classified as D (starting with the first letter of the diamond). Diamond color * * * is divided into 1 1 grades, which are arranged in descending alphabetical order from D to Z, with D being the best.

incision

Cutting, diamond cutting refers to the accuracy of its cutting and grinding ratio and the perfection after finishing. Good cutting should reflect the brightness and fire color of the diamond as much as possible, and try to keep the weight of the original stone. GIA's cutting grade is divided into excellent, very good, good, average and poor from high to low.