The 4 C’s – Cut
Cut is the only characteristic of a diamond that is man-made. The cut of a diamond refers to the proportions of the diamond – its depth, width and symmetry. How well these work together determines how well a diamond sparkles and shines.
The cut of a stone does not refer to the shape into which the diamond has been cut; rather how the light will react to the gemstone as it both enters and then exits the stone’s surface.
Of all the shapes available, round diamonds are the shape most capable of being cut to exude the greatest brilliance. The brilliance is determined by the ability of the cut diamond to reflect light.
The diamond whose width and depth is cut correctly will make the light entering it bounce from one side to another, and then back up to the table to make the whole stone radiate brilliance. A quality cut diamond will have facets angled to reflect the greatest amount of light.
But a diamond must have a good polish for the light to pass effortlessly through the stone to create the brilliance and shine.
The width of a diamond is measured through its girdle which is the widest part of the diamond where the top and bottom halves of the stone meet. The “crown” refers to the top of the diamond while the bottom is called the “pavilion”.
The depth of the diamond is the measure from its largest facet located on top of the crown, to the culet which is the smallest facet right at the bottom of the pavilion.
To ensure that the light bounces back up from the bottom of the diamond, the cut must be neither too wide at the girdle nor too short at the pavilion. This shallow cutting would leave the diamond dull in appearance.
However if the cut of the diamond is too deep, the light entering it will bounce off to the side, making the diamond appear dark. This would occur if the girdle is too slim and the pavilion too long.
Only when all of the facets of a diamond are aligned correctly, is it considered to be symmetrical. Light will then bounce from one facet to another bringing out the diamond’s full brilliance.