Copper, one of the first metals to be used by humans, is a chemical element with an atomic number of 29 and an atomic weight of 63.546; its atomic symbol is Cu. In its solid state, copper is extremely ductile and durable; it withstands temperature changes without breaking and is an excellent thermal and electrical conductor. Copper melts at 1983.7° F (1084.6 °C), is non-magnetic, and exhibits low chemical activity. The word copper was derived from cuprum, the Latin term for Cyprus, where most of the Roman supply of copper was mined.

Native copper—pure copper found in nature—was once abundant in the United States; the largest known deposits of native copper were found in the Keweenaw Peninsula of northern Michigan. Now most copper is refined from such ores as chalcocite, chalcopyrite, bornite, cuprite, malachite, and azurite, and it is mined primarily in Zambia, Zaire, Zimbabwe, Peru...