In the United States, Arizona is among the leaders in the production of silver, copper, molybdenum, gemstones and perlite. Arizona copper production accounts for 65 percent of the total U.S. mine production. There are 72 mining companies operating 126 mines in the state and more than 15,000 people are directly employed by the mining industry. The major Arizona mining companies are Asarco, BHP Billiton and Freeport-McMoRan.
