Uranium mining in the United States 1954 in the Sierra Nevada of Kern County, along the Kern River about northeast of Bakersfield. Two mines, the Kergon mine and the Miracle mine, made small shipments in 1954 and 1955. Uranium occurs as uraninite and autunite in shear zones in granodiorite. Accessory minerals include fluorite and the molybdenum minerals ilsemanite and jordisite. The first uranium identified in the US was pitchblende from the Wood gold mine at Central City, Colorado in 1871. Uranium mining in southwest Colorado goes back to 1898. The Uravan district of Colorado and Utah supplied about half the world's radium from 1910 to 1922,
Uranium tungsten and gold (19.3 g/cm). Uranium metal reacts with almost all non-metal elements (with the exception of the noble gases) and their compounds, with reactivity increasing with temperature. Hydrochloric and nitric acids dissolve uranium, but non-oxidizing acids other than hydrochloric acid attack the element very slowly. When finely divided, it can react with cold water; in air, uranium metal becomes coated with a dark layer of uranium oxide. Uranium in ores is extracted chemically and converted into uranium dioxide or other chemical forms usable in industry. Uranium-235 was the first isotope that was found to be fissile. Other naturally occurring