The refractive index of diamonds is basically the same, mainly because diamonds are equiaxed crystals and their optical properties are isotropic. The refractive index is basically fixed at 2.4 17, so the refractive index is also a powerful parameter to judge the authenticity of diamonds.

Diamond color grade:

Colorless is the highest grade, and the darker the tone, the worse the quality. In the classification of colorless diamonds, the top color is D, arranged in the order of Z, D-F is colorless, G-J is almost colorless, and there is basically no collection significance from K down. The ring holder below k color, gold is also very nice.

Because diamonds will gradually turn yellow from K, when choosing diamonds, choose the color above H. I-J grade also belongs to the category of near colorless, but a trace of yellowish diamonds with yellow, green, blue, brown, pink, orange, red, black and purple are precious and expensive among diamonds. Red diamonds are the most expensive.