Fancy Cut Fancy Cut

Cut has the biggest impact on the beauty of diamonds and the least amount of difference in their price. The word cut has several meanings when it comes to diamonds. The cut of a diamond does not just mean its shape (round brilliant, princess, oval, cushion, etc.) but also addresses the symmetry, polishing, angles and the proportions of each physical aspect of the diamond.

The cut determines the diamond's sparkle. A properly cut diamond will refract the light that enters the diamond and return it through the top to produce the much desired sparkle. The angles have to be exactly right to effectively reflect the light back to your eye.

The typical brilliant cut diamond is cut with 57 facets, 33 on the crown and 24 on the pavilion. On a well-proportioned stone, these facets will be uniform and symmetrical. If they are not, the diamond's ability to refract and reflect light will suffer.

Fancy Cut

Cutting a raw diamond into a faceted and polished gem-quality stone is a multi-step process. Each step is critical to the final outcome. The steps are:

Name Description
Marking: A rough stone is marked prior to cleaving or sawing to determine the direction of the grain and cleavage, eliminate waste, and bypass any inclusions or imperfections. The natural shape of the rough stone will also be a major factor in deciding how to cut the stone. An octahedron can be cut into one or two Round Brilliants but a square Princess cut will result in the least amount of waste due to the square shape of the stone. Asymmetrical crystals such as macles are used primarily for fancy cuts. Cubic shapes are ideal for a square Princess or Radiant cut. High-tech computerized helium and oxygen analyzers are now used to evaluate a stone prior to cutting.
Cleaving: Cleaving refers to splitting a stone along its grain by striking it. A rough stone is cleaved if there are conspicuous defects and/or inclusions which would prevent it from being made into a single gemstone. Cleavage is the tendency of crystalline materials to split along defined cleavage plane. Due to its atomic structure, a diamond can be cleaved in four directions parallel to each of the four octahedron crystal faces. Cleaving is a critical step as a mistake by the "cleaver" could fracture, or shatter the stone.
Sawing: A stone-cutting saw is a thin disk made of phosphor bronze. As the saw blade rotates it continues to pickup or "recharge" itself with diamond dust which is the cutting agent. It can take several hours for the saw blade to cut through a 1k rough diamond.
Bruiting: The rough diamond is placed in a chuck on a lathe. While the rough stone rotates on the diamond lathe, a second diamond mounted on a dop is pressed against it, rounding the rough diamond into a conical shape. This step is also referred to as "rounding."
Faceting: To facet a round brilliant, the "blocker" or "lapper" will cut the first 18 main facets, then a "brillianteer" will cut and polish the remaining 40 facets. The cutting (also called "placing") and polishing of each facet is accomplished by attaching the stone to a top stick with cement, then pressing it against a revolving cast iron disk, on a scaife, or lap that has been "charged" with diamond dust. During this faceting stage the angles of each facet must be cut to an exacting standard in order to yield maximum brilliancy, and maintain symmetry.

Fancy Cut