AM_Cordierite_1 Formula: (Si5.031 Al3.969) (Mg1.91 Fe.08 Mn.01) Na.05 K.02 Ca.02 H1.12 O18.56 Name: Cordierite Unit cell: 17.079 9.73 9.356 90.0 90.0 90.0 , V=1554.77 Space group: CCCM (66)

Cohen J P , Ross F K , Gibbs G V , American Mineralogist , 62 (1977) p.67-78, An X-Ray and neutron diffraction study of hydrous low cordierite