Understanding Diamond Polish

Polish refers to how well a diamond has been “finished off” by the diamond cutter, which is then measured by a gemologist. When a diamond is cut and polished, microscopic surface imperfections may be created by the polishing wheel as it drags tiny dislodged crystals across the surface of the stone. How severe the damage is directly affects the polish grade the diamond is given.

Excellent
The diamond is an ideal example of how clean the finish of the diamond is and flaws are not visible to the naked eye, nor at 10x magnification.
Very Good
The diamond has the bare minimum of minor surface imperfections, which again are invisible to the naked eye and only visible under 10x magnification by a skilled grader.
Good
The stone has minor imperfections that are unlikely to be seen with the naked eye but visible under 10x magnification.
Fair
The diamond has medium visible imperfections that can be seen with the naked eye.
Poor
The diamond has significant surface graining which impacts on the beauty of the stone.

For diamonds with a polish grade of Excellent to Good, any polishing defects are not visible to the naked eye and should have no impact on the diamond’s overall appearance.