The term "Polish" refers to the overall condition of the surfaces of a finished diamond. A rating is assigned based on the amount of polishing lines that are visible. These polishing lines are caused by very small diamond crystals which are embedded in the polishing wheels used by diamond cutters to polish the surface of the diamond after cutting. Diamond polish is important because it can affect the degree to which light is able to pass through a diamond therefore making it more or less brilliant. Diamonds that are laboratory certified with a good, very good or excellent polish rating are the most desirable. Diamonds that have poor polish will be less brilliant and not as desirable or valuable.
Fine Jewelry Pros Diamonds™are graded after examining the diamond, facet by facet and assigning one of these five polish ratings:
There is not a big difference between the 'Excellent' and 'Very Good' ratings to the unaided eye. The differences could be more visible only when a stone is magnified. However, a rating of 'Fair' or 'Poor' means that the flaws in the polish are noticeable to the unaided eye and will have some affect on the overall beauty of the diamond.
The polish grading is included on the Fine Jewelry Pros Diamond™ Certificate of Authenticity.
Poorly polished facets may reduce the intensity of light reflected from, or refracted into and out of a diamond. This can affect the brilliance and visual performance of diamond. When a diamond has a 'Good' or lower polish gradingthe stone may appear as if it needs to be cleaned.