"White copper" is a term generally used to describe various alloys of copper and nickel in which there is enough nickel present for the distinct reddish copper color to be lost. It doesn't take much nickel for that to happen. For example, since 1866, US five-cent pieces, commonly called "nickels," have been made from a white copper alloy comprising three parts copper and one part nickel by weight. US three-cent pieces were made from the same alloy from 1865 to 1889. Both coins, copper-nickel five-cent and three-cent pieces, have a silvery appearance, and neither looks like it is made mostly of copper.

Please take note: Since US nickels are three-quarters copper, they are not attracted to a magnet, at least not noticibly attracted to an ordinary household magnet. Canadian nickels, on the other hand, are made from unalloyed pure nickel, and are thus readily attracted to a magnet.