Diamond Facets

The Importance of the Cut of Diamond Facets
The quality of a diamond is dependent upon the cut of the facets which reflect the brilliance, fire, sparkle and luster of a diamond. In 1458 Lodewyk (Louis) van Berquem of Brugge, Belgium created the first cut diamonds when  he discovered that they could be cut by their own dust. Louis van Berquem invented a diamond polishing wheel called a scaif which enabled him to cut the facets of a diamond. Berquem also introduced the concept of using absolute symmetry in the placement of facets on diamonds. From this point diamonds were used as ornaments in jewelry and the process and different techniques for diamond cutting were gradually developed.

Diamond Cuts
Diamond Cutting

Diamond Facets - Facets produce the sparkle
What exactly are facets? Diamond facets are the smooth surface areas of a diamond which have been cut, polished and positioned at different angles which allow light to enter and reflect back from the stone. The depth and width and the uniformity of the facets control the brilliance and the durability of a diamond. The quality of the facets of a diamond are the major determining factor in enhancing the diamond's ability to sparkle or reflect light and play a large part in the resulting brilliance of the stone. The following general definitions will help with increasing understanding of diamond Facets:
 

Diamonds are Forever...
An Impartial Guide to Diamonds

• Definition of Brilliance: The amount of sparkle a stone gives off through the reflection and refraction of light
• Definition of Sparkle: A measure of the light reflected out by a diamond as it is viewed from different angles
• Definition of Dispersion: Dispersion refers to the prism of light refracted from within a cut and polished diamond and relates to the sparkling colors that are emitted from the stone as it is viewed from different angles
• Definition of Fluorescence: An inherent property possessed by diamonds resulting in glowing without an appreciable rise of temperature when exposed to ultra-violet rays, cathode rays etc.
• Definition of Lustre / luster: Term used to describe the brightness of an object that shines with reflected light rather than producing its own
• Scintillation: Occurs when light bounces among the facets creating a really sparkling display
• Definition of Culet: A tiny flat facet that cutters sometimes add at the bottom of a diamond's pavilion. Its purpose is to protect the tip of the pavilion from being chipped or damaged

Cabochon or Convex Cuts - An Unfaceted Gemstone
Definition of a Cabochon: A modification to the gemstone face that creates a highly polished, convex-cut, unfaceted gem that is smooth to the touch. When a stone receives one or two convex faces with or without facets at the base, it is said to be convex cut, (e.g Almandine Garnet). But when its facets are simply polished, it is said to be cut 'en cabochon' as in the Opal and Cat's-eye. In ancient times the Sapphire was always so cut. A stone cut with a flattish convex surface is said to be tallow-topped.