Recognized for its unusual pyrite matrix, Morenci turquoise comes from southeast Arizona, near the New Mexico border. Colored from light to bright blue, the stone is named for the Morenci Copper mine. The Morenci mine is the largest copper mine in the USA, and was first claimed in 1864 as the Longfellow mine, producing 20 million pounds of copper. At one time, large turquoise deposits were buried by the owners of the copper mine, to keep their workers busy with copper. In 1956 turquoise mining rights were granted to William “Lucky” Brown, and large quantities of turquoise were produced. Lucky’s sons mined the site until the lease ended in 1984. The mine is no longer leased to private enterprises, and high grade Morenci turquoise is prized and can be difficult to obtain.