Here is an unusual one! This specimen shows sharp chalcopyrite crystals that totally cover a matrix of sphalerite. Speckled on the chalcopyrite crystals are bladed crystals of enargite. Now, I was surprised when I saw them but looked on mindat and one of the pictures on mindat.org look exactly like the enargite crystals on chalco in this specimen! Very cool, unusual mineral specimen from this prolific lead-zinc mining area of the Tri-State fields.