AM_Fredrikssonite Formula: Mg3.92 Fe.48 Mn1.56 Al.04 B2 O10 Name: Fredrikssonite Unit cell: 9.198 12.528 2.965 90.0 90.0 90.0 , V=341.66 Space group: PBAM (55)

Burns P C , Cooper M A , Hawthorne F C , The Canadian Mineralogist , 32 (1994) p.397-403, Jahn-Teller-distorted MnO6 octahedra in fredrikssonite, the fourth polymorph, of Mg2Mn(BO3)O2