Various articles of moderate-priced to inexpensive jewelry, originally pieces suitable for a particular type of costume but now applied to two classes of jewelry: gem-set imitations, which resemble precious jewelry but are made of silver (sometimes rhodium-coated) or pinchbeck and set with substitutes for gemstones, e.g. marcasite, paste or synthetic gemstones; although usually the stones are cemented, some are hand-set.
Articles made of some base metal and imitations of gemstones, being intended as a novelty and to meet an ephemeral fashion trend. Such latter articles are today usually purchasable at various types of shops other than jewellers; although much is mass-produced, some well-designed and rather costly examples have been made for leading couturiers, such as Chanel, Christian Dior, etc.
The introduction of costume jewelry occurred in the 18th century, but its development and extended use were during the 19th century, especially in England when mass-produced jewelry was made by the Birmingham factory of Matthew Boulton.
When such pieces are made of materials of reasonable value and designed and made with skill and artistry, they may be considered to be within the meaning of the term 'jewelry'.
From: An Illustrated Dictionary of Jewelry, autor: Harold Newman, publishers: Thames and Hudson