AM_Cryptomelane
Formula: K.65 Na.11 Sr.08 Mn3.76 Fe.16 Al.08 O8
Name: Cryptomelane
Unit cell: 9.956 2.8705 9.706 90.0 90.95 90.0 , V=277.35
Space group: I12/M1 (12)

Post J E , Von Dreele R B , Buseck P R , Acta Crystallographica, Section B , 38 (1982) p.1056-1065, Symmetry and cation displacements in hollandites:, structure refinements of hollandite, cryptomelane and priderite, Locality: Chindwara, India, Note: -1M polytype, Note: Anisotropic displacement factors from ICSD