Glossary

Alloy  Two or more elemental metals can be combined to make a compound or alloy.  This is done to change the visual properties such as color, or working properties such as increasing hardness, denseness, corrosion resistance and others.

Black Pearls   Technically a “South Sea” pearl, it is cultivated by a special variety of the Pinctada oyster.

Carat  Unit of weight used for gemstones. One carat = 0.2 grams.

Crown  Term for the upper part of the faceted stone.

GIA   Gemological Institute of America

Gold-Filled   This term refers to a material (usually base metal), on which a layer of gold has been bonded by fusing.

Fusing   Method of connecting pieces of metal by heating them to their melting point and allowing the surfaces to melt together.

Karat  The relative amount of gold in an alloy is called Karat.

Nacre   Outer layer of the pearl.  Nacre is the same substance that forms the lining of the shell.  It is composed of microscopic crystals of calcium carbonate.

Nickel   Nickel is hard white metal used primarily as an alloying ingredient.

Ounce             Unit of weight (troy ounce) used for precious metals.  One ounce (oz) = 31.1 grams or 20 pennyweights (dwt)

Palladium   Metal of the platinum group.

Pavillion   Term for the lower part of a faceted stone.

Pennyweights  Unit of weight used for precious metal. One pennyweight (dtw) = 1.5 grams.

Rhodium   White metal from the platinum group.  Used to plate over silver in order to inhibite tarnishing.

Soldering   Process of joining two pieces of metal by using a third metal with a lower melting point.

South Sea Pearls   These pearls are very large, white pearls often called the “queen” of cultured pearls. They are produced by a particular type of unusually large saltwater oyster, the pinctada maxima.

Sterling   Term for a silver alloy containig 925 parts silver and 75 parts copper.

Tarnish   Another name for corrosion on metals.