The quality of diamonds is usually measured by weight (carat), color, clarity (transparency) and cutting standard internationally. The abbreviation 4C is the first English letter of four measurement items: carat, color, clarity and cut.

1 carat

In the case of excellent color, transparency and cutting, the larger the single particle, the more valuable the diamond is. The weight of diamonds is calculated in carats, 1 carat = 0.2g, 1 carat = 100 minutes.

2 colors

Color grades can be roughly divided into five grades from D to Z. Among them, D, E and F are the best (colorless), D is the best, and E and F are the second. After that, G, H, I and J are nearly colorless. After that, K-Z is colored, K, L, M (light yellow) is yellowish, and N-Z is the worst (extremely light yellow, light yellow) yellowish.

3 Transparency

Brightness and transparency can be divided into five grades: F to I, and F and IF are the best grades, almost transparent, very precious and rare. VVS 1 and VVS2 are high-grade products. Followed by SI 1 and SI2. Then I 1, I2, I3.

4 cutting

The suggested finish of cutting can be divided into six grades, namely excellent, very good, good, medium, average and poor.