Cut refers to how a diamond is transformed from a piece of dull rough into the beautiful gem that adorns her hand. Cut is the one and only variable that is controlled by man. It is cut that is responsible for the amount of brilliance and fire, resulting in a diamond that sparkles and shows a play of color when light hits it. The earliest diamonds were nothing like their beautiful counterparts of today.
The Diamond Cutting Process
Cutting diamonds requires much experience, skill, and patience. Cutters apprentice for many years under the watchful eye of a Master. A rough diamond will be passed through many hands on its journey to the final polish.
The first step in the cutting process is marking the rough. The cutter will plan the cutting of the rough and mark it accordingly. He will determine what inclusions can be eliminated, how well the stone will be proportioned and how large the final gem will be.
After marking, the stone will be given to a cutter for splitting either by a process known as cleaving (splitting the stone parallel to the grain) or sawing (splitting the stone by sawing through the crystal against the grain). Sawing is a difficult process that can take several hours and literally be done one millimeter at a time.
The next step in the process is called bruting or rounding. This is when the girdle will be shaped and the cone that will become the pavilion is fashioned. The cutter tries to retain as much of the rough as possible in keeping with the original goals. The result could be that the diamond has something called a girdle natural which is retention of part of the original skin of the rough to eliminate unnecessary loss of weight, and is considered the mark of good craftsmanship.
The next step is performed by the blocker. This is when the culet, the four bezel facets on the crown, and the four pavilion mains are fashioned. The rest of the faceting is accomplished in the step called brillianteering which adds 24 crown facets and 16 pavilion facets.
Lastly, the diamond will be ready for its final polish when any external blemishes like girdle fringing is removed and the diamond is finished as the beautiful gem that will out-shine all others.