Dims: 2.4" x 2.3" x 1.6"(6.1 x 5.8 x 4.1 cm)
Wt: 6.06 oz.(172.0 g)
Kisenge Mine, Zaire
On a heavy botryoidal base of various manganese oxides rest hundreds of small crystals of Polianite, a variety of Pyrolusite that has unusually large, thick crystals. These crystals are only about 2 x 1 x 1 mm in dimensions, but it is enough so that one can easily see their prismatic form, square-to-rectangular cross-sections, and wedge-like terminations without a loupe or magnifier. The crystals and their base are colored a dark gray (polianite from the Greek word polia, meanging "grayness", in allusion to its color), have a submetallic luster, and are opaque. There is a moderate amount of damage in the form of crushed crystals and broken botryoidal formations. The base rock is also made up of Pyrolusite, and strongly resembles formations of psilomelane, showing layers of material that are alternately waxy and metallic in luster. It is the first piece of this particular variety that I have ever seen.