Kobyashevite, Cu sub(5)(SO sub(4)) sub(2)(OH) sub(6)4H sub(2)O, a new devilline-group mineral from the Vishnevye Mountains, South Urals, Russia

A new mineral kobyashevite, Cu sub(5)(SO sub(4)) sub(2)(OH) sub(6)4H sub(2)O (IMA 2011-066), was found at the Kapital'naya mine, Vishnevye Mountains, South Urals, Russia. It is a supergene mineral that occurs in cavities of a calcite-quartz vein with pyrite and chalcopyrite. Kobyashevite forms elongated crystals up to 0.2 mm typically curved or split and combined into thin crusts up to 12 mm. Kobyashevite is bluish-green to turquoise-coloured. Lustre is vitreous. Mohs hardness is 21/2. Cleavage is {010} distinct. D(calc.) is 3.16 g/cm super(3). Kobyashevite is optically biaxial (-), alpha 1.602(4), beta 1.666(5), gamma 1.679(5), 2 V(meas.) 50(10) degree . The chemical composition (wt%, electron-microprobe data) is: CuO 57.72, ZnO 0.09, FeO 0.28, SO sub(3) 23.52, H sub(2)O(calc.) 18.39, total 100.00. The empirical formula, calculated based on 18 O, is: Cu sub(4.96)Fe sub(0.03)Zn sub(0.01)S sub(2.01)O sub( 8.04)(OH) sub(5.96)4H sub(2)O. Kobyashevite is triclinic.