AM_Cordierite
Formula: Al4 Si5 (Mg1.54 Fe.46) O18.48 Li.12 Na.1 Ca.03 K.02 H2
Name: Cordierite
Unit cell: 17.083 9.738 9.335 90.0 90.0 90.0 , V=1552.92
Space group: CCCM (66)

Gibbs G V , American Mineralogist , 51 (1966) p.1068-1087, The polymorphism of cordierite I: The crystal structure of low cordierite