Close-up of glass crystal with many facets causing dispersion spectrum from light

gemstone A gemstone (also called a fine gem, jewel, precious stone, semiprecious stone, or simply gem) is a piece of mineral crystal which, when cut or polished, is used to make jewellery, jewelry or other adornments. Certain Rock (geology), rocks (such ...

desired to be used in

jewelry Jewellery (or jewelry in American English) consists of decorative items worn for personal adornment such as brooches, ring (jewellery), rings, necklaces, earrings, pendants, bracelets, and cufflinks. Jewellery may be attached to the body or the ...

is cut, carved or made into a bead. The best quality rough is cut, also often referred to as

faceting Stella octangula as a faceting of the cube In geometry, faceting (also spelled facetting) is the process of removing parts of a polygon, polyhedron or polytope, without creating any new Vertex (geometry), vertices. New edges of a faceted po ...

. This is done by a

lapidary Lapidary () is the practice of shaping rock (geology), stone, minerals, or gemstones into decorative items such as cabochons, engraved gems (including cameo (carving), cameos), and faceted designs. A person who practices lapidary techniques of ...

who decides how to reshape the gemstone using his knowledge of the

refractive index In optics, the refractive index (or refraction index) of an optical medium is the ratio of the apparent speed of light in the air or vacuum to the speed in the medium. The refractive index determines how much the path of light is bent, or refrac ...

of gemstones to maximise any particular crystal's colour or play of light. As a general rule, a cut gemstone will be reduced in mass (in carats) by about 50%. Among the several techniques used to work with gemstones are sawing, grinding,

sanding file:Schleifpapier verschiedene Sorten.jpg, upright=1.35, Sheets of sandpaper with different grit sizes (40 (coarse), 80, 150, 240, 600 (fine)) Sandpaper, also known as coated abrasive or emery paper, is a type of material that consists of sheet ...

, lapping,

polishing Polishing is the process of creating a smooth and shiny surface by rubbing it or by applying a chemical treatment, leaving a clean surface with a significant specular reflection (still limited by the index of refraction of the material accordi ...

, grilling, and tumbling. The

diamond cut A diamond cut is a style or design guide used when shaping a diamond for polishing such as the Brilliant (diamond cut), brilliant cut. Cut refers to shape (Pear cut, pear, oval), and also the symmetry, proportioning and polish of a diamond. The ...

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. How diamonds have been cut has evolved over time largely to technological advances.

Types

* Asscher cut * Baguette cut * Brilliant cut *

Briolette A briolette is a style of gemstone cut (gems), cut. It is an elongated, mostly symmetrical along the main axel, pear shape covered with angular facets usually with a pointed end and no Girdle (gemstone), girdle. It is often drilled to hang as ...

Cabochon A cabochon (; ) is a gemstone that has been shaped and polished, as opposed to faceted. The resulting form is usually a convex (rounded) obverse with a flat reverse. Cabochon was the default method of preparing gemstones before gemstone cuttin ...

* Cushion cut or old mine cut * Emerald cut * Pendeloque cut * Princess cut * Radiant cut * Rose cut * Trilliant cut, trillian or triangle cut

References

External links

* {{DEFAULTSORT:Cut (Gems) * History of jewellery Diamond

Types

See also

References

Further reading

External links