The Patch Mine near Central City in Colorado is one of the most classic localities on the front range. Gilpin County is the site of the first discovery of Gold in Colorado, and the Patch Mine (often referred to as the Glory Hole Mine) is a still standing landmark just southwest of Central City. This piece is filled with classic, sharp, semi-lustrous, opaque, black tetrahedral Sphalerite crystals wedged between two sections of Quartz matrix. Colorado collectors will tell you that obtaining specimens from Gilpin County is very difficult because the vast majority of the mining took place before WWII and good quality pieces simply are not around. A good reference specimen of this material. Largest Sphalerite crystal measures 1.2 cm on edge. Ex. Brian Kosnar Collection.