Engineering:Cut (gems)

Short description: Shaping a gemstone for use in jewelry

A decorative glass crystal about 4 cm (1.6 in) in diameter, having a facet cut often applied for gemstones. At some positions, coloured light (see rainbow colouring) can be regarded caused by the intended optical prism effect of the cut.

A gemstone desired to be used in jewelry is cut depending on the size and shape of the rough stone, as well as the desired piece of jewelry to be made. As a general rule, a cut gemstone will reduce the mass (in carats) by about 50%.

Among the several techniques used to work with gemstones are sawing, grinding, sanding, lapping, polishing, grilling, and tumbling. The diamond cut planning stage is a complex process that requires the cutter to work with unique rough stones. Very often, the location of the inclusions in a rough stone will determine the type of shape to which a diamond may be cut. For economic reasons, most diamonds are cut to retain weight instead of maximizing brilliance.

Types

Cut emeralds

Princess cut diamond set in a ring

• Asscher cut
• Baguette cut
• Brilliant cut
• Briolette
• Cabochon
• Cushion or old mine cut
• Emerald cut
• Pendeloque cut
• Princess cut
• Radiant cut
• Round brilliant
• Trilliant cut, a.k.a. trillian or triangle cut

See also

• Diamond cut

Further reading

• Warren, Larter (1936). The Line-Cut Diamond, pp.  19–20. Gemological Institute of America, USA, Vol. 2, No. 2 (Summer 1936)
• Shipley, Robert M. (1936). Gemological Glossary, pp.  7. Gemological Institute of America, USA, Vol. 2, No. 4 (Winter 1936)