What are the proportions of the diamond?

There are many shapes that a diamond may be fashioned into, such as round, pear, and oval. Cut does not refer to the shape, instead, cut refers to the quality of the proportioning,  symmetry of the facets and polish of the cuts.

The most common is the Brilliant round diamond. Round diamonds are typically cut with, 58 facets. (Flat edges). Better proportioned facets mean more light will be reflected back into the viewer's eyes. This is extremely important, because if a diamond is cut properly, it will create a more sparkling appearance.

Diamond cuts are measured by a factor called "the table percentage".  A Jeweler should be able to provide this to you, so always ask for it. Typically, a good table percentage should be between 55 and 60 percent. 

Many gemologists consider the quality of the cut to be the single most important diamond characteristic.  Even if a diamond has perfect color and clarity, a poor cut will reduced the perceived brilliance of the stone.

Aspects of a diamonds cut:
  • Diameter: The width of a diamond as measured through the girdle (see above diagram).
  • Table: The flat top and largest facet of a gemstone.
  • Crown: The top portion of a diamond extending from the girdle to the table.
  • Girdle: The narrow band around the widest part of a diamond.
  • Pavilion: The bottom portion of a diamond, extending from the girdle to the point of the stone.
  • Culet: The facet at the tip of a gemstone. (not visible with the unaided eye)
  • Depth: The height of a gemstone measured from the culet to the table.