This is the brownish-green hedenbergite crystal. Dimensions: 2.0 x 1.5 x 1.1″ (5.2 x 3.8 x 2.9cm). Weight – 2.6oz (74 grams). Origin: Russia, Dalnegorsk.
Some information about hedenbergite:
Hedenbergite, CaFeSi2O6, is the iron rich end member of the pyroxene group having a monoclinic crystal system. The mineral is extremely rarely found as a pure substance. It was named in 1819 after M.A. Ludwig Hedenberg, who was the first to define hedenbergite as a mineral. Contact metamorphic rocks high in iron are the primary geologic setting for hedenbergite. This mineral is unique because it can be found in chondrites and skarns (calc–silicate metamorphic rocks). Since it is a member of the pyroxene family, there is a great deal of interest in its importance to general geologic processes.
Hedenbergite has a number of specific properties. Its hardness is usually between five and six with two cleavage plains and conchoidal fracture. Color varies between black, greenish black, and dark brown with a resinous luster. Hedenbergite is found primarily in metamorphic rocks.