Franckeite on matrix (!)

Franckeite is a relatively rare iron, lead, tin, antimony sulfosalt, which is not often found in well-crystallized display specimens, especially on matrix! This is one of the very few specimens of Franckeite that I have seen from the famous Siglo XX mine, and certainly one of the most eye-catching. This piece hosts several groups of Franckeite consisting of somewhat "sword"-shaped crystals forming spherical aggregates which are sitting on minor iridescent Sphalerite and/or Wurtzite with minor associated Pyrite and Quartz on matrix. A great quality specimen for somebody looking to own a rare and attractive "black" mineral. This is also a good opportunity to acquire something that is rarely offered in the open market, especially on such attractive matrix! This species belongs to the only group of minerals that forms in naturally "round" or "cylindrical" shaped crystals. This specimen was collected in August of 2010 and is an excellent example of the material. There were only a handful of good specimens, and well crystallized pieces ON MATRIX like this are few and far between from any locality. A wonderful, rare species from one of the most classic mines in Bolivia! Specimen # BOL711B14