Diamond Cut Properties
by Lars Larsen
October 13, 2010 / Diamond Education
The three principal properties by which the cut quality or make of a diamond is graded are the PROPORTIONS, SYMMETRY and POLISH.
The PROPORTIONS, or relative dimensions, establish the principal angles of reflection and essentially determine the amount of light that is returned from the top of a Diamond.
Table Width, Crown Height, Pavilion Depth, Total Depth and Girdle Thickness (taken as a percentage of the diameter of width), Crown Angle and Pavilion Angle are all considered when grading the proportions of the cut.
IDEAL PROPORTIONS are those which lie within an accepted, narrowly defined range, mathematically calculated to produce the maximum overall amount of light return and an optimum balance between brilliance and fire.
SYMMETRY refers to the uniformity of the Shape or Girdle Outline and to the precision of the shape, position and alignment of the facets. The higher the degree of symmetry, the more evenly spread and balanced is the light performance.
SUPER SYMMETRY refers to the highest degree of symmetry which is readily observed in Super Ideal Cut diamonds which display the highly distinctive, perfectly symmetrical light patterns commonly referred to as Hearts & Arrows.
POLISH refers to the quality of the surface finish in which lustre (reflectivity) and any surface imperfections are considered. Intensity or strength of light return is directly related to the quality of the polish.
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