Cuprostibite is an extremely rare copper antimony thallium mineral that was first described in 1969 from Mount Nakkaalaaq in Ilímaussaq complex, Narsaq, Greenland. Showing all of the classic features from this discovery, this large miniature specimen from the superb systematic collection assembled by the brothers Martin and Michael Günther (1951-2007 & 1956-2021) is labelled as from Taseq Area, which incorporates Mount Nakkaalaaq. Showing a range of rock-forming minerals in the matrix, the Cuprostibite forms purplish metallic masses (crystals of this species are unheard of other than in human-made industrial slag) to 4 to 5 mm across, with flashes of bright blue and green secondary copper minerals scattered upon the rock surface. A great size example of this extremely rare species from the Type Locality area.
