Cronstedtite (very rare) (ex Brian Kosnar Collection)

Item Description

A very rarely seen specimen of Cronstedtite from the world famous Siglo XX mine in Bolivia. Cronstedtite is a rare iron silicate belonging to the serpentine group. This exceptionally rare and eye-catching specimen is filled with lustrous, black, trigonal crystals forming spherical aggregates on a thin crust of iron-stained matrix. The crystals have been photographed under the microscope to better illustrate their quality. Additionally, there are some micro orange crystals of an unknown species on the piece (possibly Florencite, Natanite, Wickmanite??) These specimens are exceptionally difficult to find on the market, and this particular specimen was mined in 2006, and comes from the collection of noted Bolivian expert, Brian Kosnar. According the Brian, only a handful were found, and he reports that he has yet to see any more specimens over the last several years.