FLUORITE
Specimen flu-64
$ 125.00Dims: 4.4" x 3.7" x 2.4" (11.2 x 9.4 x 6.1 cm)
Wt: 1 lb., 3.4 oz. (551 g)
Denton Mine, Cave-In-Rock, Illinois, U.S.A.
This hand specimen consists of a cluster of several cubic Fluorite crystals- I count at least 20 different crystals, though many of these are mostly incomplete. They are generally in very good condition, showing a few scars along the corners of one or two cubes and the inevitable damage from the piece's separation from its place of formation. The largest of these cubes has visible dimensions of 1.4 x 1.0 x 1.0" (3.6 x 2.5 x 2.5 cm) and like the others, is incomplete due to heavy intergrowth. As seen in the close-up image, these crystals have formed in such a way that their edges continued to grow for a while after their faces stopped. Thus, some of the crystals show a partially complete "crust" of violet Fluorite over a dull-golden "core". Both the core and crust are transparent and quite clear, and have a pearly-to-waxy luster. Off of the center of the cluster is an outcropping of sphalerite. It has a black color with brown highlights and a bright, vitreous luster, and is opaque. There is a thin layer of calcareous shale or mudstone host rock on the specimen's underside.