tsumgallite

The type specimen is from material collected in the early 1960s, from the second oxidation zone, by TCL mineralogist Bruno Geier. Samples of this material, consisting of vuggy tennantite - germanite ore with colourless crystals of söhngeite and an unidentified mineral, were provided to Georg Gebhard by Geier’s son. Tsumgallite, IMA 2002-011, was described by Schlüter et al. (2003) and named for the locality (Tsumeb) and its gallium content. The holotype specimen is conserved in the Mineralogisches Museum, Universität Hamburg, Germany (catalogue number TS 509).

Tsumgallite forms scaly mica-like aggregates, less than 1 mm across, on tennantite - germanite ore. The colour of tsumgallite is pale greenish-yellow to beige and it is translucent with a pearly lustre; individual thin, platy crystals do not exceed 40μm in size (Schlüter et al. 2003).

Tsumgallite was formerly designated as the unknown "Mineral GF" (of Keller 1977a; see Pinch and Wilson, 1977).

abellaite; chalcocite; gallite; germanite; quartz; renierite; siderite; söhngeite; tennantite-(Zn); thénardite (?)