Arsenuranospathite


Arsenuranospathite is a rare mineral with the chemical formula Al22F·20H2O. The name "arsenuranospathite" as arsenate analog of uranospathite was first used by Walenta with reference to a uranyl-arsenate mineral from Black Forest massif, Germany.
Later it was undoubtedly demonstrated that the name arsenuranospathite was applied, at least, to two different speciesproper arsenuranospathite, ideally Al22F·20H2O, orthorhombic, and its partially dehydrated analogue, Al22F·nH2O, 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.

Chemical composition

Contents of Al and U are very stable. 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