About 30 years ago, there were a handful of very good quality Arsenopyrite specimens on the market from the San Jose mine, but they all seemed to have dried up. This is a very attractive specimen of this material because it is just covered with small, sharp, bright, prismatic Arsenopyrite crystals plus golden Pyrite crystals on matrix. The largest Arsenopyrite crystal measures 8 mm in length. This piece was mined in 1980 and is a great example of this old material from one of the most famous mines in the Bolivian tin belt.