Schaurteite, Ca3Ge(SO4)2(OH)6·3H2O

This report presents the first crystal structure determination of the mineral schaurteite, ideally Ca(3)Ge(SO(4))(2)(OH)(6)·3H(2)O, tricalcium germanium bis-(sulfate) hexa-hydroxide trihydrate. This single-crystal X-ray diffraction study investigated a natural sample from the type locality at Tsumeb, Namibia. Schaurteite is a member of the fleischerite group of minerals, which also includes fleischerite, despujolsite, and mallestigite. The structure of schaurteite consists of slabs of Ca(O,OH,H(2)O)(8) polyhedra (site symmetry mm2) inter-leaved with a mixed layer of Ge(OH)(6) octa-hedra (-3m.) and SO(4) tetra-hedra (3m.). There are two H atoms in the asymmetric unit, both located by full-matrix refinement, and both forming O-H⋯O hydrogen bonds.