Franckeite (superb thumbnail)

Item Description

This is one of the rarest sulfosalts in the world. This specimen is a very rich, incredibly rare, superb quality, crystallized specimen of the triclinic lead, tin, iron, antimony sulfosalt Franckeite consisting of somewhat "sword"-shaped crystals oriented into spherical aggregates forming a killer thumbnail display specimen. There are some minor acicular grey "needles" of another sulfosalt (possibly Jamesonite, Berthierite or Boulangerite) and a small cube of Galena on the specimen as well. This piece is a top notch thumbnail specimen for somebody looking to own a rare and highly displayable piece of an exceptionally rare mineral. I would personally give this specimen a perfect "10" in competition, this is about as good as they get. This piece is rather aesthetic compared to many other "flat" or two-dimensional pieces of the material that I have seen from San Jose. A 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 specimen is over 30 years old and was part of the best find of the material. There were only a handful of good specimens, and well crystallized display pieces like this (especially on matrix) are few and far between.