Arsenuranospathite

Arsenuranospathite is a rare mineral with the chemical formula Al(UO2)2(AsO4)2F·20H2O.[1] The name "arsenuranospathite" as arsenate analog of uranospathite[2] was first used by Walenta (1963)[3] with reference to a uranyl-arsenate mineral from Black Forest (Schwarzwald) massif, Germany.

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Later it was undoubtedly demonstrated that the name arsenuranospathite was applied, at least, to two different species – proper arsenuranospathite, ideally Al(UO2)2(AsO4)2F·20H2O, orthorhombic, and its partially dehydrated analogue, Al(UO2)2(AsO4)2F·nH2O (n = 8–10), tetragonal or pseudo-tetragonal.

Properties

Yellow to yellow-greenish, transparent to opaque tabular and prismatic crystals, with perfect cleavage. Transparent to translucent. Hardness = ∼2. Radioactive.[4]

Chemical composition

Contents of Al and U are very stable (1±0.05 and 2±0.07 atoms per As+P+U = 4 apfu respectively). Main variations of chemical compositions are connected with the ratio As:P and the content of F.

Occurrences

Sophia Mine, Böckelsbach valley, Wittichen, Schenkenzell, Black Forest, Baden-Württemberg, Germany[2]

See also
  • Chistyakovaite

References
  1. Chukanov, N.V.; et al. "Arsenuranospathite, Al(UO2)2(ASO) 2F·20OH2O: Formula revision and relationships with allied uranyl arsenates and phosphates".
  2. "handbookofmineralogy".
  3. Walenta, Kurt (1978). "Uranospathite and arsenuranospathite". Mineralogical Magazine. 42 (321): 117–128. Bibcode:1978MinM...42..117W. doi:10.1180/minmag.1978.042.321.18.
  4. http://www.handbookofmineralogy.org/pdfs/arsenuranospathite
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