Cattle Grid pit, Mt. Gunson Mine, Pernatty Lagoon, South Australia
Thumbnail, 1.5 x 1.3 x 0.7 cm
A significant specimen of a very rare copper bismuth sulfide: this is a sharp thumbnail crystal which was collected over 30 years ago from this now-defunct copper and bismuth mine. It has great form, and a very interesting luster with hints of iridescence. These are the finest known examples of the species by several orders of magnitudes. Reportedly, and an article in the Mineralogical Record will provide the full story some time next year, a mine geologist kept 30 crystals as samples found when the mine was working in the early 1980s. All others, including much other material of other species, went to the crushers and was smelted. Nowhere in the world have such large and sharp crystals of this magnitude been found before or since.