Copper

Unknown Owner

Classic loose cluster of nicely crystallized native copper for this famous locality. In great condition.The Ray Mine, situated in the Mineral Creek district of Pinal County, Arizona, is a premier copper deposit known for its exceptional crystallized copper specimens. Geologically, the site is a classic porphyry copper deposit where mineralization occurred during the Laramide Orogeny as hydrothermal fluids deposited copper within Precambrian schist and igneous intrusions. The mine is particularly famous for producing aesthetic native copper in various habits, including spinel-law twins, arborescent sprays, and delicate wire formations, often associated with bright green chrysocolla or white quartz. Historically, the area was first explored by Spanish prospectors, but organized mining began in the 1880s with the Mineral Creek Mining Company. Large-scale industrial production commenced in 1911 under the Ray Consolidated Copper Company, which pioneered the use of underground block-caving methods. In 1948, the operation transitioned to a massive open-pit quarrying system that continues to this day under the ownership of ASARCO. Spanning over a century of continuous activity, the Ray Mine remains one of the largest and most productive copper mines in the United States, providing a steady supply of both industrial ore and world-class mineral specimens.