As of 2015, zinc, copper and nickel are used for making coins in the United States. Historically, a variety of metals have been used to make coins.
The earliest metal coins, which were made of small bronze pieces, originated in China in 1500 B.C. and were used for trade, while coins with guarantees, which often served as a promise to the government, originated in 650 B.C.
The value of coins was most often chosen based on the value of the metals used to make them, as well as the durability of those metals. In the United States, gold and silver were once used in coin making, but as a result of the increasing cost of these metals, as of 2015, they are used only for making bullion coins and collector coins.