A nicely composed specimen of Cosalite (a lead-bismuth sulfosalt) on Quartz. The Cosalite presents as aggregates of radiating fibrous dark lead-gray crystals sitting on a Quartz crystal cluster. A superb specimen. Specimens like this are not seen often on the market today. 
 
Pequa Rare Minerals label accompanies the specimen. 
Ex. David S. Burgess collection.
 
Karaobinskoye deposit
Karaoba region
Kazakhstan