Takeuchiite

General Information: Chemical Formula:Mg2Mn+++O2(BO3) Composition:(Molecular Weight = 253.16 gm)Magnesium 19.20 % MgManganese 21.70 % MnBoron 8.54 % B Oxygen 50.56 % O  Empirical Formula: Mg2Mn3+O2(BO3) Environment:In dolomite. IMA Status:Approved IMA 1980 Locality:Lanban, Varmland, Sweden. Name Origin:Named for Yoshio Takeuchi (1924-), Japanese mineralogistPhysical Properties: Cleavage:None Color:black. Density:3.93 Diaphaniety:Opaque Hardness:6 - Orthoclase Luster:Metallic Streak:brownMore details...

(Mg,Mn)2(Mn,Fe)BO5