Diamond Polish: What You Need To Know

Brilliant Cut Diamond Ring
Brilliant Cut Diamond Ring

The finish of the diamond has two important attributes which are Symmetry and Polish. Polishing of the diamond occurs after the diamond has been cut and faceted. It is this process that gives the shine and the smoothness that we see to diamonds. If the polish is not done well then it can severely affect the sparkle of an otherwise perfect brilliant cut diamond engagement ring. We shall be taking a brief look at the blemishes and the various grades of polishing that you need to be aware of.

The Various Grades Of Diamond Polish 

Similar to the Symmetry Scale, there is a Polish Scale too. The polish lines together with other blemishes, visible on the surface of a diamond decides its grade.


This is the grade for when there are no blemishes and polish lines are at 10 x magnifications. In diamonds of this grade, light can enter and exit the stone without affecting its sparkle or brilliance.

Very good

This grade includes the visibility of minute polish lines and blemishes that may have little to no impact on the sparkle of the diamond. Even with its flaws, diamonds in this grade can be called as an excellent cut grade.


This is the grade for when there are visible polish lines and blemishes when viewed under a 10 x magnification. There is an effect on the sparkle and the brilliance of the diamond because the light is not able to perfectly enter the diamond and exit it. This grade can utmostly earn a very good grade.

Fair And Poor 

This is the grade when there are noticeable finishing errors and marks in the form of blemishes and polish lines. There is an effect on the light performance, and it vastly reduces the diamond’s ability to sparkle and shine. This results in a poor brilliant cut diamond ring.

Examples Of Polish Lines

  • Polish lines: these are the small groves that are located on the facets that are the results of diamond polishing. There is a difference from the surface graining as they don’t cross the facet junctions.
  • Nick: this is the chip or notch in the diamond surface that doesn’t have depth.
  • Extra facet: while manufacturing, they add an extra facet to remove inclusions.
  • Pit: this is a tiny white spot which is generally observed on the skin of the diamond. It resembles a white dot.
  • Abrasions: these are the small micks and cuts at the facet junctions, which is a result of the wear and tear.

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