It is the only one of the 4 C’s that is influenced by the human hand and has a direct affect on a diamonds beauty.
The cut of a diamond refers its proportion and is a crucial element when selecting a diamond. Through cutting and polishing facets onto a rough diamond, the cutter creates facets known as the crown, culet, table, girdle and pavilion of the diamond. More than any other aspect cut unleashes a diamonds sparkle and optimum brilliance.
The cut determines the stone’s shimmering sparkle when it encounters light.In a perfectly cut diamond the cutter may need to cut away more than 50% of the rough diamond.
A diamond that has been perfectly cut and polished will reflect almost all of the light that caresses it from above – the light passes through the top, bounces from one mirror-like facet to another, and then travels back out the top, giving the diamond maximum brilliance and scintillation.
At times a cutter will sacrifice a perfect cut to create a stone that is larger in carat weight. Diamonds that are cut too shallow or too deep lose or leak light through the side or bottom, therefore resulting in a diamond with diminished brilliance and scintillation and therefore beauty.
Round diamonds are considered the most brilliant of all diamond shapes as they are symmetrical and can follow specific proportional guidelines. This then allows it to reflect nearly all the light the enters it.
Fancy Shapes – non-round diamonds, are cut with much greater proportional range variations. However, they too have guidelines that allow them to be considered well cut.