• Grades:Excellent-EX, Very Good-VG, Good-G, Fair-F, Poor-P
  • Equipment:10x magnification triplet loupe, digital diamond gauge, expert ideal scope, microscope
  • While most of the diamond's qualities are determined by nature, the quality of the cut is based on the skill of the professional and sometimes depends on business considerations. The cut grade determines the light performance of the diamond and indicates a combination of several important parameters. The most important of these are table proportion, total depth, crown and pavilion angle, girdle thickness and culet size. This category contains five ratings: Excellent, Very Good, Good, Fair and Poor.

    The quality of the cut depends on specific proportions, but is always decided by a professional. A diamond with perfect proportions can only be rated “very good” if the symmetry and polish subcategory rating falls into the Good grade. Similarly, if a diamond's depth, table and girdle are all in the perfect category, but these values are all on the borderline, then the final cut grade is likely to be lower.