Copper, an essential mineral, is naturally present in some foods and is available as a dietary supplement. It is a cofactor for several enzymes (known as "cuproenzymes") involved in energy production, iron metabolism, neuropeptide activation, connective tissue synthesis, and neurotransmitter synthesis. It’s classified as a native element. Copper's metallic luster attracted people's attention. Today most copper is produced from sulfide ores. Copper is an excellent conductor of electricity. Most copper mined today is used to conduct electricity - mostly as wiring.