When one thinks of Bismuthinite one tends to conjure up images of thin filament-like acicular crystals spanning cavities, or slightly wider blades totally enclosed in vein material. Large, freestanding, 3-dimensional crystals such as these in this amazing miniature specimen are really the preserve of Tazna mine in Potosí Department, Bolivia. Indeed, this mine is one of the richest bismuth deposits in the world and one of the few places where ores of bismuth are specifically mined, rather than the metal being obtained as a byproduct of other mining. Individually, the crystals reach nearly 3 cm in length and are not heavily coated in oxidation products like many specimens from Tazna mine. Indeed, the crystals are dark grey and quite lustrous, with a metallic to sub-metallic appearance. They form a network of intergrown 'blades' the bases of which are rough and ragged, but highly lustrous, where they are detached from surrounding rock or other crystals, but the edges of the crystals are very fine, with occasional vertical growth-lines and sharp, tapering, pointed terminations. It is from the superb systematic collection assembled by brothers Martin and Michael Günther (1951-2007 & 1956-2021) and comes with a purpose made Sunnywood acryllic display stand. Certainly an imposing Bismuthinite.
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