Dims: 4.7 x 3.6 x 1.9" (11.9 x 9.1 x 4.8 cm)
Wt: 12.8 oz. (363 g)
At least 20 Calcite crystals rest on the shale host rock of this hand specimen. These crystals reach maximum dimensions of 0.6 x 0.5 x 0.4" (1.5 x 1.3 x 1.0 cm) and are generally in very good condition, as only a few spots of damage are visible- one of these is rather severe, however. They have excellent trigonal "nailhead" form, though some of them are rather warped and others are more prismatic than tabular in nature. Most of them have a pale, rust-red coloration and are transparent and dimly to moderately clear. I think, though, that the rust coloration is caused by a thin coating over the crystals; light reflected off of their faces (which possess a pearl luster) shows iridescent red, orange, and yellow colors (see the close-up image). These crystals rest on a base of what appears to be dull brown, opaque calcite or aragonite that has an irregular, warped form. This base in turn rests on a thin crust of greenish-gray shale. I have been told that such specimens likely come from India, but the shale base makes me doubtful.