Dims: 0.9x0.8x0.7" (2.3x2.1x1.9 cm)
Wt: 1.5 oz. (41.0g)
Rio Vilace, Dept. La Paz, Bolivia
Although this specimen of natural native bismuth does not show any outward crystal faces, there is abundant evidence of crystal form in the exposed cleavage faces, plus hints of trigonal structure in the outside surface of the nugget. It looks like this specimen was a stream tumbled nugget which was broken open to expose the inner crystals. The cleavage and fracture surfaces are excellent and have a bright metallic luster, while the weathered outer surface is dull. One interesting fact - the outside has a dozen or so pits, each of which is lined with a light brown mineral and contains a clear crystal which I suspect is a calcite, although the crystals are rounded and distorted enough that I can't tell for sure.