Diamond Cut

Cut

Cut is used to describe the reflective qualities of a diamond and refers to the quality and preciseness of a diamond's outline, its shape and the placement and alignment of its facets. These factors, when ideal, contribute to maximize the stone's brilliance.

The Cut grade is divided into three categories:

Cut compares the diamond's proportions to best light performance pre-calculations. The calculations of the diamond's proportions are carried out using laser measuring machines and manual confirmation. This category is graded in one of the following categories: Excellent, Very good, Good, Fair and Poor, and is available for round brilliant diamonds only.

Symmetry refers to the quality of a diamond's exactness of its outline, and the shape, placement and alignment of its facts. Symmetry, which is inspected according to its visual appearance as seen by the naked eye and under magnification, is graded in one of the following categories: Excellent, Very good, Good, Fair and Poor.

Polish refers to the quality of a diamond's smoothness of its surface. Polish, which is inspected according to its visual appearance as seen under magnification, is graded in one of the following categories: Excellent, Very good, Good, Fair and Poor.

For round brilliant diamonds, in addition to the cut categories, an honorary comment can be added to each diamond that possesses high grades of cut and symmetry. The honorary comment awarded depends on the diamond's exact proportions and may be either Excellent Ideal Cut, Platinum Cut or Premium Cut.

The EGL Platinum criteria for receiving an honorary comment are:

  Excellent Ideal Cut Platinum Cut Premium Cut
Total Depth 59.2 - 62.4% 58.0 - 63.8% 58.0 - 63.8%
Table Size 53.0 - 61.0% 53.0 - 61.0% 53.0 - 61.0%
Crown Height
(Crown Angle)
13.0 - 17.0%
(32.5 - 35.4°)
14.0 - 16.0% 13.0 - 17.0%
Pavilion Depth 41.5 - 44.4% 42.2 - 43.8% 41.7 - 45.0%
Pavilion Angle 39.7 - 41.7° 40.0 - 41.3° 39.7 - 42.0°
Girdle Thickness Very Thin – Slightly Thick Very Thin – Slightly Thick Very Thin – Slightly Thick

An additional honorary comment is 8 Hearts and 8 Arrows which represents a perfect alignment between the crown's and the pavilion's facets.

 

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