AM_Gonnardite_8 Formula: Na1.462 Ca.474 (Si2.685 Al2.315) O14 H4 Name: Gonnardite Unit cell: 12.959 12.959 6.5446 90.0 90.0 90.0 , V=1099.07 Space group: I-42D (122)

Lee Y , Hriljac J A , Parise J B , Vogt T , American Mineralogist , 91 (2006) p.247-251, Pressure-induced hydration in zeolite tetranatrolite, Locality: Mt. Saint-Hilaire, Quebec, Canada, Note: P = 4.2 GPa, Note: high-pressure superhydrated phase