Sphalerite on Siderite

From my own personal collection, this cabinet sized display specimen is a quintessential Gilman sulfide / carbonate association piece. Several remarkably sharp AND lustrous crystals of jet-black Sphalerite with notably SMOOTH faces – hardly any striations at all on many faces – are gently intermixed and sitting atop a crystallized “plate” of soft beige-cream-colored compressed rhombohedra or “discs” of Siderite. The piece was mined in 1978, and I actually received this piece as a gift from my father as a teenager. With only a slight rough spot on one crystal, this specimen is in better condition than most from this mine.

The Eagle Mine was the center of lead and zinc mining in Colorado for a time and produced some of the state’s most memorable mineral specimens, along with the neighboring Groundhog Mine that produced the finest Wire Gold specimens in the world extant!

Ex. Brian Kosnar collection

Specimen# CO712B76