Dims: 2.4" x 1.4" x 1.1" (6.1 x 3.6 x 2.8 cm)
Wt: 1.53 oz. (43.5 g)
Mose Hill, Magnet Cove, Arkansas, U.S.A.
This small hand specimen from the well-known Magnet Cove locality consists of several pseudohexagonal dipyramidal Brookite crystals; these rest on a base made up of several intersecting, dark-gray quartz crystals. The largest Brookite crystal has dimensions of 0.3 x 0.3 x 0.2" (0.8 x 0.8 x 0.5 cm) and shows a much less perfect form than the smaller crystals, but it seems to show evidence of an accompanying sulfide mineral, as there is a small golden metallic patch of material on it, along with some blue iridescence. Other than that, all of the crystals are black, opaque, and have a luster that hangs between adamantine and submetallic. There are at least 12 of them, and the intergrown quartz crystals on which they rest have a dull, waxy-to-pearly luster and are opaque. They also have discernable but very warped hexagonal prismatic forms; I think that these traits are related to the inclusions that give them their dark gray color. A few of the quartz crystals show fresh breakage, but most are undamaged. It has not been easy for us to find Brookite specimens, even from this nearby locality.