Corkit a bariofarmakosiderit-Q z Vysoké u Havlíčkova Brodu (Česká republika)
Ivana Jebavá, Stanislav Kopecký, Petr Pauliš
Supergene mineralization with corkite and bariopharmacosiderite-Q, formed by alteration of primary arsenopyrite and galena, was found at the Vysoká hill situated 5 km in the south-east direction from Havlíčkův Brod, Czech Republic. The corkite, PbFe3(SO4)(PO4)(OH)6, formed small (below 2 mm) crystals or crystalline clusters with glassy lustre and green or brown-green colour. The bariopharmacosiderite-Q, BaFe4(AsO4)3(OH)5.5H2O, formed tiny aggregates of light yellow pseudocubic crystals with size 0.02 to 0.05 mm. The refined unit-cell parameters for corkite are: a = 7.285(1), c = 16.831(1) and V = 773.6(1) Å3; for bariopharmacosiderite-Q are: a = 7.947(6), c = 8.046(9) and V = 508.1(4) Å3. Chemical composition of both described minerals is close to the theoretical end members.