Detailed Description

This specimen features two unusually blocky twinned bournonite crystals, together with quartz crystals. The bournonite crystals are very well-defined and lustrous, exhibiting the classic “cogwheel” form. There are two quartz crystals in association, one larger with a single termination and one small doubly-terminated crystal – both are sharp. In very good condition with minor chipping.  A really nice thumbnail-sized specimen featuring great textbook bournonite crystals.

About These Bolivian Bournonites

These bournonite crystals are from the Viboras Mine, Machacamarca District, Potosí, Bolivia. The locality has produced excellent bournonite specimens over the years, but the finds are have been sporadic, often years apart. The nature of the bournonite has varied from one find to the next, and some of the bournonite has been of modest lustre, sometimes dull, and of varying sharpness/definition. This latest find has produced sharp, lustrous bournonite crystals of the finest quality, exhibiting the classic “cogwheel” twinning.