Gold and silver in their pure states, however, are too soft for making objects that will last. Therefore, other metals are frequently combined (alloyed) with both gold and silver to make them harder.
Silver alloys usually retain their silver color. The color of gold varies with the kind and amount of other metals combined with it. Red golds contain silver, copper, and zinc. Rose gold contains no zinc. Yellow golds contain more silver and less copper than red golds. Green golds may contain cadmium and zinc. Adding iron to an alloy produces blue gold.
White gold was formerly an alloy of gold and silver, which tarnished. White gold today is usually a gold and nickel alloy. It may also contain palladium, manganese, or tin, and does not tarnish. Nu-gold, Merlin’s Gold, and jewelers’ bronze are alloys of copper and zinc. They contain no gold.
Sterling silver is an alloy containing 92.5 parts silver and 7.5 parts other metal. It is also called 92.5 percent silver or 925 fineness. Although copper is the standard metal used in sterling silver, other metals may be used.
Jewelry silver, used more in Europe than it is in the United States, is often 800 fineness, which means that it is an alloy of 80 percent silver and 20 percent other metal, usually copper.
Spring silver is Sterling silver that is hardened to give it the “spring” needed for items such as money clips. Coin silver is an alloy of varying amounts of silver and copper. Sheffield plate is two thin sheets of silver with a sheet of copper fused between them.