Katophorite

General Information: Chemical Formula:Na(CaNa)Fe++4(Al,Fe+++)Si7AlO22(OH)2 Composition:(Molecular Weight = 953.22 gm)Sodium 4.82 % NaCalcium 4.20 % CaAluminum 4.95 % AlIron 24.90 % FeSilicon 20.62 % SiHydrogen 0.21 % H Oxygen 40.28 % O  Empirical Formula: Na2CaFe2+4Al0.75Fe3+0.25Si7AlO22(OH)2 Environment:Found in basic alkaline igneous rocks. IMA Status:Approved IMA 1997 Locality:La Tabatiere, PQ, Canada and the Christiania region, Norway. Name Origin:Named from the Greek for "carrying down", in allusion to its volcanic origin.Physical Properties: Cleavage:[110] Perfect, [010] Parting Density:3.2 - 3.5, Average = 3.35 Diaphaniety:Translucent Hardness:5 - ApatiteMore details...