Whilst all other characteristics of a diamond are natural, the cut is the only one directly determined by man. Many think that the cut is nothing more than the shape of the diamond, but it is actually so much more than that. As well as the shape, it also affects the proportions, symmetry and the “make” (the polish of the finished stone).
The sparkle that a diamond gives of is known as its brilliance, whilst the spectrum of colours is referred to as its fire. This is all down to the cut of the diamond, and if it is cut correctly, with the correct proportions, then the light will refract within the diamond, bouncing its facets before exiting once more out of the top of the diamond.
To effectively achieve the correct refraction, the diamond must be cut to particular proportions. The crown angle, pavilion depth and table size must all be accounted for, and if these are not proportioned correctly, the light will leak from the pavilion facets, reducing the diamond's brilliance and fire.
Diamonds can be cut in many ways and still retain the required dimensions, but the most popular is the round brilliant cut, which has eightfold symmetry and makes best use of rough octahedral diamonds. This is the classic shape that has become synonymous with diamonds, although here at Marlow's we have a variety of different cuts to suit all requirements.