Bournonite (“cogwheels”) black Considering the millions of tons

Considering the millions of tons of tin ore that Bolivia has yielded

Specimen# CO712B131

this was one of only a handful of crystals recovered according to my source who acquired them directly at the locality

which is typically what you would expect out of a metamorphic contact like this

Bournonite (“cogwheels”) black Considering the millions of tonsA hard to find "cogwheel" group of sharp, thick, blocky modified twinned crystals of Bournonite with excellent metallic luster. The piece displays well from a few angles. The stacked appearance of the crystals, combined with the bright luster, makes this one of the more eye catching smaller Bournonites available. Specimen # BOL711B23