AM_Gerstmannite
Formula: Mn.786 Mg1.214 Zn Si (O6 H2)
Name: Gerstmannite
Unit cell: 8.185 18.65 6.256 90.0 90.0 90.0 , V=954.98
Space group: BBCM (64)

Moore P B , Araki T , American Mineralogist , 62 (1977) p.51-59, Gerstmannite, a new zinc silicate mineral and a novel cubic close-packed oxide, structure