If a diamond is poorly cut, no amount of good color and clarity can make up for it. That’s why a diamond’s cut and proportions are pre-eminently significant. It is what makes a rough stone sparkle and shine; what transforms it into a dazzling gem.
A diamond’s facets, or flat planes on the stone, as they have been cut and polished will realize the amount of light that refracts through the diamond. Therefore the better the cut, the finer the luminescence.
The following terms apply to parts of a faceted diamond, and will help in describing an ideal cut versus ones that are either too deep or too shallow. (Non-faceted stones are called cabochons.)
Crown – The top part of the diamond.
Girdle – The edge or border of the diamond.
Pavilion – The bottom part of the diamond, measured from the girdle to the bottom point.
Culet – The lowest point of the diamond. In certain stones, this may be partially open.
Table – The flat top of the diamond, and its largest facet. Also called the face.
Table Spread – The width of the table facet, often given as a percentage of the total width of the diamond.
There are several ways that a diamond may appear to be improperly cut:
– If the table is centered but not symmetrical
– When the table is off-center and asymmetrical
– If the crown is too shallow (extremely thin)
– When the crown is too heavy (extremely thick)
– If the pavilion is too shallow
– When the pavilion is too deep