A nice example of bournonite on quartz.  This was one of two examples I was able to get with a strong quartz association-- this one has a lustrous group of "cogwheels" nestled near the edge of the quartz cluster.  The metallic bournonite and have a very nice contrast, and the association gives a very Herrodsfoodt-y appearance... except the faces of the bournonite aren't nearly as messy as the average Herrodsfoot piece.