Copper is a metallic element known for its reddish-brown coloration and luster. It is signified by the atomic symbol Cu and is notable for its high thermal and electrical conductivity, which is second only to silver among elements. Twenty-eight isotopes of copper are known to exist.
Copper is rarely found in its natural state, with most copper coming from minerals, such as cuprite, malachite, azurite, chalcopyrite and bornite. Significant amounts of copper ore exist in parts of the Americas and Africa. The most common uses of copper include electrical wiring, coin production, plumbing and the production of alloys. Humans have used copper for at least 10,000 years.