The 'half dime' was a silver coin, valued at five cents, formerly minted in the U.S. with production beginning on 1792. In the 1860s, powerful interests promoted the use of 'copper-nickel alloy' and the production of five cents coins was introduced in 1866.

The symbol of copper is Cu and the melting point is 1357.77 K (1084.62 deg C, 1984.32 deg F). The nickel has the symbol Ni and melting point is 1728 K (1455 deg C, 2651 deg F).

The 'shield nickel' was the first U.S. five-cent coin to be made of Cu-Ni alloy of which American nickels are struck today. The coin was issued from 1866 until 1883 and designed by James B.Longcre (August 11,1794-January 1,1869). The 'liberty head nickel' was an American five-cent piece struck for circulation from 1883 (replacing 'shield nickel') until 1912 designed by Charles Barber (November 16,1840-February18,1917). The 'buffalo nickel' or 'India head nickel' was a Cu-Ni five-cent piece that was struck by U.S.Mint from 1913 to 1936, designed by sculptor James Eagle Fraser (November 4,1876-October 11,1953). All Three coins had the same mass of 5.00g (0.1615 troy oz), diameter about 21 mm (0.8350 m) and composed of 75% Cu and 25% Ni.

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