Copper is a chemical element with the symbol Cu and atomic number 29. It
is a ductile metal with very high thermal and electrical conductivity. Pure
copper is soft and malleable; a freshly exposed surface has a reddish-orange
color. It is used as a conductor of heat and electricity, a building material,
and a constituent of various metal alloys.
The metal and its alloys have been used for thousands of years.
Roman era, copper was principally mined on Cyprus, hence the origin of the name
of the metal as сyprium or metal of Cyprus. It was later shortened to сuprum.
Its compounds are commonly encountered as copper salts, which often impart blue
or green colors to minerals such as azurite and turquoise and have been widely
used historically as pigments. Architectural structures built with copper
corrode to give a green verdigris or patina. Decorative art prominently
features copper both by itself and as part of pigments.
is essential to all living organisms as a trace dietary mineral because it is a
key constituent of the respiratory enzyme complex cytochrome c oxidase. Copper is
present in the Earth's crust at a concentration of about 50 parts per million where
it occurs as native copper or in minerals such as the copper sulfides
chalcopyrite and chalcocite, copper carbonates azurite and malachite and the
copper oxide mineral cuprite. The largest mass of elemental copper discovered
weighed 420 tons and was found in 1857 on the Keweenaw Peninsula in Michigan.