Franckeite (very rare) (ex Rich Kosnar Collection)

Item Description

This specimen is over 60 years old and was part of one of the best finds of the material right after the end of WWII. Only a handful of good specimens made their way to the United States, and well crystallized are few and far between. This is one of the rarest sulfosalts in the world. This specimen is a very rich, incredibly rare, crystallized specimen of the triclinic lead, tin, iron, antimony sulfosalt Franckeite consisting of small bladed crystals forming spherical aggregate. A good quality display specimen for somebody looking to own a rare and attractive "black" mineral. It is also good opportunity to acquire something that is rarely offered in the open market for a great price. This species belongs to the only group of minerals that forms in naturally "round" or "cylindrical" shaped crystals. This piece was from Rich Kosnar's well known Bolivian Collection, and the label indicates that it was once in the collection of the father of Bolivian Mineralogy, Federico Ahlfeld.