This matrix specimen is mostly comprised of REALLY LARGE, classic, "cogwheel twinned," bournonite crystals to 7.0 cm across. The crystals have a matte battleship-metal hue and luster to them. This is a classic locality and style but crystals in this size are very uncommon and hard to get in good specimens. There are also a few lustrous, slightly translucent, orangey, sphalerite crystals present near the bottom of the specimen. The largest sphalerite is .7 cm across. The piece is complete all around and almost free of any damage. It is really a significant worldwide bournonite, I think! And these somehow sell for a fraction of the cost of similar sized crystals from Bolivia or England.