Dims: 6.8" x 2.8" x 2.7" (15.2 x 7.1 x 6.9 cm)
Wt: 1 lb., 1.5 oz. (496 g)
Hardin County, Illinois, U.S.A.
A few dozen Sphalerite crystals rest on the dolomitic limestone host rock of this specimen. The largest crystal measures about 0.9 x 0.7 x 0.7" (2.3 x 1.8 x 1.8 cm), and though it shows considerable damage, all of the rest are in excellent condion. Their form is a complex variation of tetrahedron, and their edges show intense gradation, so it appears that their faces are highly striated. This feature is intensified by their subadamantine luster and their dark, brown-black coloration. Needless to say, the crystals are opaque to all intents and purposes. Accompanying the Sphalerites are many small, curved blades of dolomite that have a white color and a dull luster. There is also a single, pale yellow calcite crystal that is in the form of a six-sided prism with a shallow, three-sided pyramidal termination. It has a bright pearly luster and is transparent and relatively clear, though inclusions cloud a portion of it.