Located 20 miles southwest of Tucson, the Sielita Mine, now operated by Freeport McMorran, is one of the world’s largest copper-molybdenum mining operations.

Originally explored in 1895, it was not until 60 years later that Harrison Schmidt determined its value as a disseminated porphyry copper deposit. Mass produced in 1959.

Milling operations started in 1970. The production of the important secondary copper sulfide minerals chalcosite and cobelite is noted, with molybdenite containing 100 and 3,000 parts per million of rhenium. – per billion of the Earth’s crust.

Milled on site, the Sielita mine is currently the only domestic source of rhenium, a metal used by the aerospace industry as a superalloy in jet engines and industrial gas turbine engines. Known for its heat and corrosion resistance, rhenium extends engine life and enhances performance and operational efficiency, as seen in use with high octane, unleaded gasoline.

Freeport-McMoran Copper & Gold’s Sierrita refinery recovers rhenium from gases released during roasting of molybdenite concentrates and dissolved rhenium from flue sulfuric acid.

Miners were first drawn to the Mineral Creek mining district in the valley between the Tortilla and Dripping Spring Mountains in search of silver deposits in the 1870s. The disseminated chalco of Pinarschist, classified as a very fine, medium-grained metasedimentary rock that developed into a small amount of copper production by Ray Copper Co. over the next decade, and whose geological surveys produced 1.7 billion deposits. Turned out to be a secondary concentrate of the site. A few years ago.

Development began with underground mining, then moved to open pit mining by 1955, and continues to be dumped and heap leached to this day. Lae Mine is known for its well-carved mineral specimens, including native copper and cuprite.

Although not famous for its production volume, the Evening Star Mine (also known as the Old Queen Group) in the Big Horn Mining District of Maricopa County produces the rare lead-chromate mineral Phenicroit and the rare lead Forna Mineral. It is famous for the discovery of many rare minerals, such as the site. , chromic copper arsenate hydroxide minerals, and Wickenburgite, a secondary lead mineral formed from the oxidation of lead ore.

The 500-square-kilometer Bighorn Mountains in Midwest Arizona are known for their complex geology. Early prospectors were drawn to the area’s iron oxide-stained quartz veins. The Evening Star His Mine contains six of his claims first discovered by Frank Robinson in 1949. The produce included lead from Precambrian granite and gneiss, as well as small amounts of gold, silver and copper. Development included a 69-foot shaft and a 197-foot incline.

At 5,500 feet above sea level, the Crown King Mine was the most economically profitable mine from 1875 to 1885. A gold mine producing over $1.2 million in silver, he was one of the most productive silver mines in Yavapai County.

The geology of the mine consists of Precambrian schist and granite, quartzite and rhyolite fissure veins of silver and traces of gold, and three parallel ledges over 15 feet above the surface. . Silver mineralization was found in the form of seragilite (horn silver), along with minor amounts of embolite (silver chloride and silver bromide) and bromylite (silver bromide). Trace amounts of argentite and gold were also found along with copper, antimony and zinc from sulfide ores found at lower mine levels.

The Mistake Mine is a 21-acre prospective claim in the Box Canyon Mining District of Yavapai County, noted for its ramsdellite mineral specimens. Ramsdellite is a rare manganese oxide that forms in veins and layered manganese deposits. Discovered in 1954, this former surface and underground manganese mining facility is now overseen by the Bureau of Land Management.

Lesser-known mining areas include S Claims and O Claims, a prospective pit and trench claim group east of Wickenburg. Discovered here were some fine purple octahedra of quartz, cerusite, lead carbonate on barite crystals, and fluorite of zippeite. A rare uranium mineral classified as hydrated potassium uranyl sulfate hydroxide.

Zippeite is formed as a secondary mineral and is also formed on rock surfaces by efflorescence. This is the process by which the evaporation of water comes into contact with dry air. Another obscure locality known as the Kullman-McCool Mine includes the Dripping Springs Mountains brick mines, lead-silver mines, Lower D & H mines, and the famous Finch Mine (Barking Spider Mine).

Mineralization occurs in contact zones between limestone and igneous porphyry, dikes, fissures, fissures and bedding planes. Mining in the area dates back to 1880, and by 1930 over 130 mining claims had been filed, mining for vanadium, molybdenum, zinc and copper by the London Arizona Consolidated Copper Company. The area is of interest to mineral collectors, including the Finch Mine, known for wulfenite crystals with thin layers of drussy quartz. The lower D&H claim includes ctenacite, a rare sulfate mineral.

The Silver Hill Mine, located 41 miles northwest of Tucson in the Waterman Mountains, was first explored in the late 1800s and produced sporadically until the late 1940s. Production included a minimum of 16,000 tons of ore, including copper, silver, lead and some gold. Consisting of 400-foot and 300-foot shafts, the mine has a production history that includes 120 units of copper and lead ore shipped to the El Paso Smelter in the 1940s.

Copper recovery then involved recovering 8-12 pounds of copper per 1,000 gallons of water from the mine water. The ore occurs as a substitute for limestone and is a mixture of carbonates and sulfides. Mineral collectors have been drawn to sites where clumps of the rare secondary mineral osarizawaite, crystalline from auricalcite, rosasite, smithsonite, and glassy botryoids, have been found in oxidized zones over lead-bearing sediments. increase.