Slavkovite, Cu13(AsO4)6(AsO3OH)4 . 23 H2O, a new mineral species from Horní Slavkov and Jáchymov, Czech Republic: Description and crystal structure determination
Abstract
Slavkovite, Cu13(AsO4)6(AsO3OH)4 . 23H2O, is a newly discovered supergene mineral from the Geschieber vein, Svornost mine at the Jachymov (St. Joachimsthal) ore district, Czech Republic, commonly associated with lavendulan, geminite, lindackerite and ondrušite.
It forms coatings of pale green rosettes up to 1 mm across or individual spherical aggregates up to 5 mm across. Individual acicular to lath-like crystals are up to 1 mm long and 0.05 mm thick, and are colorless with a greenish tint.
Slavkovite is pale green, translucent (aggregates) to colorless with a greenish tint, transparent (crystals). It has a white streak and a vitreous luster, and does not fluoresce under both short-and long-wave ultraviolet light.
The cleavage on (011) is perfect, and on (010), it is good. The Mohs hardness is similar to 3.5-4; slavkovite is very brittle, with an irregular fracture.
The all structural and chemical data are given in the paper.