Kentrolite

General Information: Chemical Formula:Pb2Mn+++2Si2O9 Composition:(Molecular Weight = 724.44 gm)Manganese 15.17 % MnSilicon 7.75 % SiLead 57.20 % PbOxygen 19.88 % O  Empirical Formula: Pb2Mn3+2Si2O9 Locality:Vermland, Sweden.Physical Properties: Cleavage:[110] Distinct Color:dark reddish brown or reddish black. Density:6.19 Diaphaniety:Translucent to subtranslucent Habits:Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline)., Crystalline - Fine - Occurs as well-formed fine sized crystals., Wheat Sheaf - Bundle shaped aggregates resembling wheat sheafs after hand reaping wheat. Hardness:5 - Apatite Luster:Sub Metallic Streak:dark brownMore details...