What is the 4C standard in diamond ring? What do different English letters mean?

Carat, as a unit of weight, originated from the seeds of Oryza sativa L. on the Mediterranean coast of Europe, with red flowers and brown nuts in pods, about 15cm long, which can be used to make glue. There is a strange phenomenon in carob trees. No matter where it grows, it bears the same weight of nuts. Historically, this fruit has been used as a weight to measure weight. Over time, it has become a unit of weight for weighing precious and subtle substances. It was not until 1907 that it was internationally recognized as a unit of measurement for gems, and it is still in use today.

The second unit of diamond weight unit is minute, 100 minute 1 carat; A 0. 1 carat diamond is 10 cent.

Clarity of diamond

The cleanliness of diamonds is based on the observation results of diamonds under 10 times magnifying glass. It includes two aspects, that is, the original defects of gemstones and the damage to the diamond surface during processing. Clarity can be divided into the following six levels:

Flawless, FL for short.

There are no flaws inside or outside the diamond. Some glitches can also be included in the FL level.

Internal cleanliness (if any).

There is no flaw inside, but there is a little flaw on the surface.

Very, very subtle internal defect level (including very, very subtle)

There are minor defects, which can only be observed from the pavilion or have minor defects on the surface. The difference between VVS 1 and VVS2 is that VVS2 has tiny cotton spots and stubbles (basically nothing is lacking).

Very slight inclusion, referred to as VS 1 or VS2.

You can see very tiny flaws, and you can clearly see the size and position. The difference between VS 1 and VS2 is that VS2 may have fine cotton wool and stubble.

Slightly contained, referred to as SI 1 and SI2.

You can clearly see the defects.

Inperfect, I 1, I2, I3 for short.

You can clearly see the flaws, and sometimes you can clearly see the obvious cleavage.

There is a uniform mark on the cleanliness of diamonds in the world, which is generally marked in the corresponding position of the diamond morphology map of the appraisal certificate.

Diamond cutting method

In the 4c of a diamond, the most important thing is to cut the work, because no matter how clean, chromatic and even carat a diamond is, it is naturally generated by the diamond, and because of this, each diamond is more unique. According to the proportion grade and decoration grade, the cutting grade is divided into three categories: very good, good and general. Cutting contrast:

Cut too deep: When the diamond is cut too deep, the light will escape from the bottom, so the brightness of the diamond will be damaged and its center will become dark.

Cut too shallow: if the diamond is cut too shallow, the light will escape from its pavilion, and the brightness of the diamond will be damaged, losing its luster and becoming dim.

The color of diamonds

The main colors of diamonds are colorless, white, light yellow and yellow.

Divided into: D, Britain, Hong Kong and Britain ...

Hong Kong's evaluation of diamond color is that colorless to yellow is divided into 100 colors by colorimeter, so it is called "Baise Grade", which is adopted in China. Gemological Institute of the United States is colorless to yellow, and it is divided into D, E, F, …, U, V, W and other color grades, which are adopted by De Beers Company of South Africa.

At present, the evaluation of diamond color grading mostly adopts the comparison method, that is, under the standard white diamond lamp, the diamond to be graded is compared with the "standard diamond sample".

And knives, and exvg g.

There are many more. You can look at some jewelry websites, which have a lot of knowledge. Zhou Shengsheng's is good, so is Chow Tai Fook's.

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