Manganhumite

General Information: Chemical Formula:(Mn,Mg)7(SiO4)3(OH)2 Composition:(Molecular Weight = 641.22 gm)Magnesium 6.63 % MgManganese 44.98 % MnSilicon 13.14 % SiHydrogen 0.31 % H Oxygen 34.93 % O  Empirical Formula: Mn2+5.25Mg1.75(SiO4)3(OH)2 IMA Status:Approved IMA 1978Physical Properties: Cleavage:[010] Perfect Color:brown, brown orange, or light orange. Density:3.83 Diaphaniety:Transparent to Translucent Hardness:4 - Fluorite Luster:Vitreous (Glassy) Streak:whiteMore details...

(Mn,Mg)7(SiO4)3(OH)2