Cylindrite (very rare) (ex Kay Robertson and Sorbonne Collection)

Item Description

This is a very rare of specimen of one of the most unique species in all the mineral kingdom. Cylindrite is a lead, iron, tin, antimony sulfosalt that naturally forms in "cylinder" or "tube" shaped crystals, hence the name. I'm told that there is an explanation to their form that can be explained thusly. The crystals are composed of two sheets or layers of crystals that form in nearly parallel growth. The further these layers crystallize from the core, the more distortion or rotation is seen in the layers, which causes them to "curve" and form the unique shape. This piece features many crystals of bright silvery metallic Cylindrite on matrix. The largest crystal measures 3.5 cm long, and are notably thick for the species. The Santa Cruz Mine at Poopo is the type locality for the species, but we don't know if this piece is actually from the Santa Cruz Mine. A great opportunity for any collector to own a species rarely seen for sale in today's market. Ex Kay Robertson Collection (#1315). Kay is a prominent California collector, who specialized in European classics (see the article in the March-April, 2007 Mineralogical Record and the 50+ page article in the German Magazine "Mineralien Velt" November-December 2017). Valued at $600