The Diamond’s Polish is part of the manufacturing process of a finished diamond. After the diamond is cut and faceted, the diamond is polished to achieve a smooth surface.

Diamond Grading Scale for Polish
Grading is based upon the visibility of blemishes and other polish lines on surfaces of the finished diamond. Gemologists inspect the diamond at 10x magnification to determine the Polish grade.

Polish lines or other blemishes are not visible at 10x magnification. Light is able to perfectly enter and exit the diamond, without diluting the diamond’s sparkle or brilliance.

Very Good
There are minor polish details visible at 10x magnification. These polish lines or blemishes have no or very little impact on the diamond’s sparkle and the diffusion of light within the diamond.

There are some visible polish lines or blemishes. The diamond’s sparkle is usually affected because light is not perfectly able to penetrate the diamond.

Fair & Poor
There are noticeable finishing errors in the form of polish lines or blemishes. These blemishes have an impact on light’s transmission and reduce the diamond’s ability to sparkle. (Belgium Diamonds rarely offers these diamonds).

Polish is considered along with symmetry a secondary characteristic of the diamond’s grading and has the least impact on the diamond’s price and value. Polish also has an impact on the diamond’s brilliance when done well will lessen the diamond’s sparkle.


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