Copper-nickel alloy material. There is a yellow alloy, also called dilute gold, which is a copper-nickel alloy. The surface color is similar to gold, but it does not contain gold. The processed handicrafts look like gold ornaments. An alloy is a mixture of metal and metal or nonmetal. It is not easy to conduct electricity, its strength or hardness increases, and its melting point is lower than that of its constituent metals.