Copper is a ductile metal with very high thermal and electrical conductivity. Pure copper is rather soft and malleable and a freshly exposed surface has a pinkish or peach color. It is used as a thermal conductor, and electrical conductor, a building material, and a constituent of various metal alloys. Copper metal and alloys have been used for thousands of years and was principally mined in Cyprus. Today some countries such as Chile and the United States still have sizable reserves of the metal which are extracted through large open pit mines. However, there is a concern that the copper reserves may be insufficient to sustain the current high rate of copper consumption.

Copper (II) ions (Cu2+) are soluble in water, where they function at low concentration as bacteriostatic substances, fungicides, and wood preservatives. For this reason, copper metal can be used as a anti-germ surface thta can add to the anti-bacteriall and antimicrobial features of buildings such as hospitals. In sufficient amounts, copper salts can be poisonous to higher organisms as well. However, despite universal toxicity at high concentrations, the Cu2+ ion at lower concentrations is an essential trace nutrient to all higher plant and animal life. In animals, including humans, it is found widely in tissues, with concentration in liver, muscle and bone. It functions as a co-factor in various enzumes and in copper-based pigments.