CUT PROPORTIONS OF DIAMONDS
The word cut has a different meaning. It is synonymous with the making: a combination of operations (cleaving, sawing, bruiting, polishing) resulting in the shape of a diamond. These may have different forms and various styles: rose cut, brilliant cut, and mixed-cut….
Everything that contributes to creating certain conditions, good or bad, of brilliance, dispersion, and scintillation, intervenes with the quality of the cut. These are The proportion The polish The symmetry
PARTS OF A ROUND BRILLIANT CUT DIAMOND
The proportion:
The proportion of an ideal round brilliant is measured in percent, in accordance with its average
diameter.
The ideal round brilliant recommended by Marcel Tolkowsky has the following proportion:
Table size: 53.0%
Crown size: 16.2%
Pavilion depth: 43.1%
The ideal girdle has a thickness between 1 and 4 % of the girdle diameter. Therefore the total depth varies from 60.3 to 63.3%.
Crown height: 16.2
Girdle height: 1.0% – 4.0%
Pavilion depth: 43.1%
Total height: 63.3%
The ideal angle is:
Crown angle: 34.5 (Angle formed by the bezel facets and girdle plane).
Pavilion angle: 40.75 (Angle formed by the pavilion facets and the girdle facets)
The majority of the brilliant have proportions, which differ from the ideal proportion because in order to obtain this proportion the weight loss of the rough diamond is enormous. The variants are the table and the crown.
