Cuprosklodowskite

cuprosklodowskite

becquerelite

vandenbrandeite

compreignacite

Images

Formula: Cu(UO2)2(SiO3OH)2.6H2O
Nesosilicate (insular SiO4 groups), sklodowskite group, uranyl mineral
Crystal System: Triclinic
Specific gravity: 3.85 measured, 3.89 calculated
Hardness: 4
Streak: Greenish yellow
Colour: Yellowish green to grass-green or greenish yellow
Solubility:
Common impurities:
Very strongly RADIOACTIVE
Environments

Sedimentary environments
Hydrothermal environments

Cuprosklodowskite is a secondary mineral formed by alteration of earlier uranium minerals, both in situ and after transport of solutions. Associated minerals include becquerelite, brochantite, uranophane, kasolite, vandenbrandeite, liebigite, parauranophane and compreignacite (HOM).

Localities

At the Sonia Mine, Urcal deposit, Guandacol, Coronel Felipe Varela Department, La Rioja Province, Argentina, alteration of zirconian uraninite has produced boltwoodite as small botryoidal aggregates of fibrous crystals intimately associated with cuprosklodowskite (AM 46.12-25).

At the Huemul Mine, Pampa Amarilla mining district, Malargüe Department, Mendoza Province, Argentina, in the alteration zone above the water-table, many hydrated yellow minerals like tyuyamunite, sengierite, carnotite, cuprosklodowskite, autunite, bayleyite and andersonite are found in close association with copper minerals such as malachite, azurite and chalcanthite (AM 51.1-13).

At Port Radium District, Great Bear Lake, North Slave Region, Northwest Territories, Canada, cuprosklodowskite occurs as thin dark green coatings and minute, mammillary crusts and as thin blue-grey earthy crusts on pitchblende. Fourmarierite is found widely on the same specimen (CM 7.331-332).

At Nicholson No. 1, Consolidated Nicholson Mines, Goldfields District, Beaverlodge Lake area, Saskatchewan, Canada, cuprosklodowskite occurs as tiny bright yellow-green needles in a fissure in talcose argillaceous rock associated with other uranium minerals. It was also seen close to sulphides and malachite on a fine-grained carbonaceous rock as a coating (AM 36.411-414).

At the type locality, the Kalongwe deposit, Mutshatsha, Lualaba, DR Congo, cuprosklodowskite occurs as small acicular needles in a fissure in a talcose argillaceous rock in the uranium deposit (AM 19.235-236).

At the Woodrow mine, Laguna subdistrict, Cibola County, New Mexico, USA, unoxidised ore is composed of coffinite and uraninite, which typically are extremely finely divided and intimately mixed with a carbonaceous substance. Pyrite and marcasite are abundant also, and small amounts of chalcopyrite, galena, wurtzite, cobaltite, baryte and carbonate minerals are present. The ore is partly oxidised to a depth of about 50 feet. Owing to the low vanadium content of the deposit, the oxidised ore contains a large variety of minerals of hexa-valent uranium, including uranopilite, zippeite and cuprosklodowskite (AM 47.26-33).

At an unnamed U mine, McKinley County, New Mexico, USA santafeite is associated with hematite, limestone and cuprosklodowskite (AM 43.677-687).

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