kosmochlor

{{infobox mineral | name = Kosmochlor | image = Kosmochlor jade, Jurassic, Burma 1.jpg | imagesize = 260px | alt = | caption = Chromite (metallic black), kosmochlor pyroxene (emerald green to dark green to black), chromian jadeite pyroxene (green), chromiferous arfvedsonite amphibole (green or gray), symplectite (green, a finely-crystalline mineral mix of mostly chromian jadeite) | category = Inosilicate mineral | formula = NaCr3+Si2O67| IMAsymbol = Kos | molweight = | strunz = 9.DA.25 | dana = | system = Monoclinic | class = Prismatic (2/m) (same H-M symbol) | symmetry = C2/c | unit cell = a = 9.57, b = 8.71 c = 5.26 Å; β = 107.49°; Z = 4 | color = Emerald-green | colour = | habit = Prismatic crystals and fibrous aggregates | twinning = Simple, lamellar on {100} and {001} | cleavage = Good on {110} parting on {001} | fracture = | tenacity = | mohs = 6 | luster = Vitreous | streak = Light green | diaphaneity = Semitransparent | gravity = 3.51-3.60 | density = | polish = | opticalprop = Biaxial (-) | refractive = nα = 1.766 nγ = 1.781 | birefringence = δ = 0.015 | pleochroism = X = yellowish green; Y = blue-green, grass-green; Z = emerald-green | 2V = | dispersion = r > v | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = | prop1 = | prop1text = | references = }} Kosmochlor is a rare chromium sodium clinopyroxene with the chemical formula NaCr3+Si2O6.

The name is from German kosmisch, for its occurrence in meteorites, and the Greek chlor, for green. It was first reported in 1897 from the Toluca meteorite, Jiquipilco, Mexico.