GemstoneTerminology - Original Sin Designs

Gemstone terms and definitions

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Baroque Pearl - Oddly shaped pearls that form during cultivation

Briolette - A pear-shaped stone that is faceted

Cabochon - A dome-shaped stone without facets

Carat - A unit of mass for gemstones, equal to 0.2 gram *see Karat

Chaton - A faceted stone with a round shape.

Chatoyancy - The ability of certain gems to display a "cat's eye" or color-shifting effect, caused by the precise occurrence of narrow inclusions. Some examples are Moonstone, Labradorite, Tiger Eye

Crystal - There are two basic kinds of crystal - rock crystal and man-made.

Rock crystal - the common name for the silicate mineral, quartz, which is a semi- precious stone that occurs in nature.

Man-made crystal - is produced from a mixture of quartz and, soda, potash, and lead oxide. Swarovski is a man-made crystal. Oddly enough, rock crystal has nowhere near the color or brilliance of manufactured crystal

Cubic Zirconia - Cubic Zirconia are man made gems which appear very much like diamonds, yet do not have the same intrinsic properties such as hardness."Zircons" as they are often called, are mass produced and much less expensive than natural diamonds *see Simulant

Cultured Pearl - An oyster or mollusk is artificially "seeded" with a tiny grain of sand. The mollusk then excretes a coating to protect itself from the irritant. Several layers are accreted, creating a real pearl.

Cushion Cut - A square or rectangular stone that has rounded corners, also called "antique cut". The older form of the brilliant cut, having a girdle outline approaching a square with rounded corners

Dichroism - The ability of some gems to display a second color when viewed from a different angle. Dichroic glass, a particularly beautiful type of glass produced by glass artists, also exhibits shifting color displays

Doublet - A stone made of two components (a backing and the stone itself), generally bonded together with a clear adhesive. *see Triplet

Freshwater Pearls - Irregular pearls of various colors produced by fresh water mollusks such as mussels and clams

Geode - A hollow rock matrix usually containing crystals of one or more gemstones. Amethyst and Peridot are examples of gemstones found in geodes

Inclusions - Impurities that occur within a stone

Jade - An opaque semiprecious gemstone which is usually found in shades of green, but can be also be found in lavender, white and rose shades *see Jadeite

Jadeite - A hard, translucent variety of jade which is rarer than the other varieties of nephrite and comes in a variety of colors such as orange, pink, yellow, brown, blue, violet, and black *see Jade

Jasper - an opaque, impure, variety of quartz that may be red, yellow, or brown. It breaks with a smooth surface and can be highly polished like marble. Varieties of jasper include Fancy Jasper, Picture Jasper, Poppy Jasper, Red Jasper, and Striped (or Banded) Jasper

Jet - Black glass originally meant to simulate real jet, which is black ignite (fossilized coal)

Karat - unit of purity for gold. In the United States, karat almost exclusively means the unit of purity. 24k is pure gold,18k is 18 parts gold and 6 parts other metals (usually silver or copper), and 14k is 14 parts gold to 10 parts other metals. *see Carat

Mabe Pearl - A Japanese term for cultured pearls which are cultured against the shell so that only half a pearl is formed resembling a half-sphere

Marquis Cut - Faceted, elongated oval stone, which tapers to a point at both ends

Moonstone - A transparent, slightly iridescent, milky white variety of feldspar, with white or light blue opalescent spots

Mother-of-pearl - The pearly, irridescent material on the inside of mollusk shells like abalone, oysters, and mussels