Gallobeudantite

Gallobeudantite is a secondary, Gallium-bearing mineral of beudantite, where the Iron is replaced with Gallium, a rare-earth metal. It was first described as a distinct mineral by Jambor et al in 1996.[1] Specific Gallium minerals are generally rare and Gallium itself is usually obtained as a by-product during the processing of the ores of other metals. In particular, the main source material for Gallium is bauxite, a key ore of aluminium. However, Gallobeudantite is too rare[2] to be of economic value. Its main interest is academic and also among mineral collectors.

Jambor et al.[1] describes Gallobeudantite as having occurred as zoned rhombohedra, up to 200 μm along an edge, in vugs in a single specimen of massive Cu-bearing sulfides from Tsumeb, Namibia. Gallobeudantite can be pale yellow, greenish, or cream-colored and has a white to pale yellow streak.[3] It has a vitreous luster.

Since the discovery of Gallobeudantite, there has been renewed interest in this class of mineral, particularly in the famous Apex deposit in Utah[4] and additional studies on the crystal structure of Ga-rich plumbogummite from Tsumeb[5]

The mineral has only been found so far in the Namibian Tsumeb Mine, located in the Oshikoto Region.[6] The mineral is a mixture of three elements Gallium, Arsenic and Lead with the formula ${\displaystyle {\ce {PbGa3 [(AsO4),(SO4)]2 (OH)6}}}$.