This is an incredibly rich specimen for this rare species, the richest I know of in fact. It comes from the collection of Colorado Bureau of Mines geologist Stanley Korozel via dealer Josef Vajdak, who was until recently on his retirement one of the more noted dealers in rarities. This was said to have been collected in the 1960's. Lustrous, metallic, gray crystals of colusite, to .8 cm in length, are associated with brassy crystals of pyrite, of similar size. Colusite is a rare copper, vanadium, arsenic, tin, antimony, sulfide. The entire knob wrapping around the top is SOLID, crystallized colusite with a crystallized region of over 3 x 3 cm.