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Named for its composition of uranium (uran), calcium (cal), and carbonate (car). Urancalcarite occurs in uranium deposits in the oxidized zones in only a few localities including the Democratic Republic of the Congo and China. Urancalcarite is highly very strongly radioactive.

Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/urancalcarite.pdf


Named for the uranium in the composition and for the discovery locality at Falkenstein, which means Falcon’s Stone, after the Greek goddess Circe, which translates to “falcon.” Notable localities for Uranocircite include in the United States in Arizona, Utah, Pennsylvania, and here in the Black Hills of South Dakota at the Hart Table prospect, at Minas Gerais in Brazil, in Germany at the type locality at Bergen an der Trieb and at Schneeberg in Saxony, at Wolsendorf in Bavaria, and at Menzenschwand in the Schwarzwald Mountains, in the Czech Republic at Dametice in Bohemia, and in Spain at El Cabril in Cordoba. There are several other known localities. Uranocircite appears as yellow-green to yellow thin tabular crystals and as aggregates. It fluoresces green under ultraviolet light.

Ref. Minerals and their Localities, Bernard, J.H. and Hyršl, J. (2004)

IMA/CNMNC List of Mineral Names (2009) and Dana’s System of Mineralogy, 7th edition, 2 (1951), 987


Sometimes referred to as Uranophane-alpha, Uranophane is named for its uranium content and for the Greek word phainesthai, meaning “to appear” as its composition was originally under some scrutiny as being accurate. Uranophane is quite common, a secondary mineral in uranium deposits and formed by the alteration of uraninite. It can also be found “as coatings, presumably through deposition from meteoric waters.” There are hundreds of worldwide localities, but only a few have excellent crystals or large quantities. Uranophane is highly radioactive. Crystals will fluoresce weakly under ultraviolet light, but massive Uranophane is typically not fluorescent.

Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/uranophane-alpha.pdf


An allusion to its felt-like appearance, Uranopilite is named for the Greek pilos, meaning “felt,” and for its uranium content. Found in several locations, Uranopilite is locally abundant as a secondary mineral formed during the acid conditions produced by the oxidation of sulfides where uraninite is present. It is also possible that Uraopilite is post-mine product. Uranopilite is strongly radioactive and will strongly fluoresce a yellow to yellow-green under short- and long-wave ultraviolet light.

Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/uranopilite.pdf

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