Symmetry refers to how precisely the various facets of a diamond align and intersect. This can include extra or misshapen facets, off center culets and tables, and wavy girdles. Sometimes, a diamond cutter will deliberately allow a minor reduction in symmetry as a way of preventing a defect present in the rough stone. Symmetry typically ranges from 'Poor' to 'Excellent'.
Symmetry has a limited impact on the appearance of a diamond and a greater impact on price. A diamond with 'excellent' symmetry and polish may be priced higher than a diamond with 'good', 'fair' or 'poor,' because they are perceived as more valuable. A diamond with a lower symmetry grade will also have a higher probability of noticeable defects.
Each Fine Jewelry Pros Diamond™ Certificate displays the symmetry grade, using the following scale: