Chemistry: PbFe2+Ge6+(Ge4+2O7)(OH)2.H2O
Size: 5 mm (FOV); scale bar on image
Owner: W.W. (Bill) Pinch
Photographer: RRUFF Project

Composite crystals of pale olive-green bartelkeite (to 1.8 mm), associated with tiny, gemmy prisms of transparent, very pale-yellow mimetite (to 0.5 mm), in a vug in germanium-rich massive sulphide, comprising germanite and renierite (see Photograph 2).  The bartelkeite has been verified by single crystal XRD.

Tsumeb is the type locality for bartelkeite, which was described by Keller et al. (1981). This specimen was subsequently used to refine the structure of bartelkeite using single-crystal x-ray diffraction (Origlieri et al., 2012).

Image courtesy of RRUFF;