Définition

• Copper Nickel.  An alloy predominantly of copper, to which is added nickel for hardness and a white color. It is an ideal coinage alloy for medium to low value coins. The inherent hardness of nickel alone is well known, but the alloy of nickel with copper increases this alloy's coinability, and it has proved successful in the late 19th and all of the 20th century. Alloys of 90 copper 10 nickel are satisfactory ranging up to 75 copper 25 nickel.
  History of copper nickel.  The Swiss, in 1850, were the first to strike coins in a copper nickel, but the coinage alloy contained other metals as well (zinc, silver). The United States first used copper nickel in 1856 (88 copper, 12 nickel) for a cent denomination and continued for nine years to 1864, but replaced this with a bronze for the lowest denomination coin, only to return to copper nickel for a five-cent piece in 1866, which, for the most part, has remained in use until the present.
  Copper nickel ore was mined in German Saxony (where it was called kupfernickel) and by 1874 Germany was striking copper nickel coins. By 1879 the Swiss converted entirely to a "pure" copper nickel coinage (without other metal alloys).
  The greatest movement toward copper nickel came in 1946 when Great Britain in
  effect demonetized its coinage by going off any relationship to silver. It halted coinage
  of its "silver" composition used since 1920 (actually 50 silver, 40 copper, 5 zinc and 5 nickel – a four metal alloy called a quaternary composition). It replaced this with a copper nickel composition for all coins struck after 1947.
  Other countries followed. In 1964 the United States replaced all its silver coins (except for some commemorative and proof issues) with a copper nickel clad composition.
  Nickel is infrequently found in copper ores (along with cobalt, silver and other metals). This mineral in Germany was called nickeline (since 1832) and niccolite (since 1868). (In Canada the metal occurs with sulfide, pentandite). The metals are separated, and when required for coinage they are combined in precise mixture to from a coinage alloy.
  As a coinage metal copper nickel is also known as nickel bronze. It is called cupro-nickel in England and France; the abbreviation is cn for either spelling. Copper nickel is not hyphenated; cupro-nickel is. The Japanese call the alloy hakudo, or white bronze. Because of its hardness it is not a white metal.
  The same factors for the choice of copper nickel for coins – hardness and coinability – also makes it ideal for jewelry items to be worn. Watch makers found the alloy of particular benefit for low cost watch cases. One such alloy, called silveroid (typical of vague or deceptive jewelry terminology as it contained no silver), was formed of 54 copper, 45 nickel and 1 manganese. The Bennington Vermont Battle Centennial Medal of 1878 by George Hampden Lovett was struck in this alloy.  See composition (2), bronze (chart).

  excerpted with permission from

  An Encyclopedia of Coin and Medal Technology

  For Artists, Makers, Collectors and Curators

  COMPILED AND WRITTEN BY D. WAYNE JOHNSON

  Roger W. Burdette, Editor

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