A BIG, RICH specimen of whopper tetrahedrites from Peru! These crystals, some with a thin coating of brassy chalcopyrite, measure to 2.5 cm along the edge. There is a bit of damage to a few corners, but very modest. In the crook of the specimen is a cluster of quartz crystals that have grown on a patch of sphalerite, which is intergrown with the tetrahedrites.