Dims: 3.3" x 2.7" x 2.6"(8.4 x 6.9 x 6.6 cm)
Wt: 11.7 oz.(331 g)
Gilman, Colorado, U.S.A.
Approximately 20 rhombohedral Ankerite crystals rest on the sphalerite base of this specimen. They range in size from 2 mm to almost 0.5" (1.3 cm) in all dimensions and show a noticeable but small amount of damage. The crystals have a creamy color and pearly to waxy luster. They show a dull translucence, but damage to some of the crystals has exposed their colorless, transparent cores; only a thin layer around each crystal is translucent. These crystals are intergrown with hundreds of dark sphalerites that make up the bulk of the piece. These sphalerites occur in what appears to be a tetragonal form, though intergrowth tends to warp their shapes, and do not exceed 0.3" (8 mm) in diameter. Twinning is visible in several crystals. They have a black color, adamantine luster, and are thoroughly opaque. Besides these two minerals, there is no other material or host rock present on the specimen.