AM_Gonnardite_4 Formula: (Si2.685 Al2.315) O12.102 Na1.462 Ca.474 H8 Name: Gonnardite Unit cell: 12.9815 12.9815 6.6808 90.0 90.0 90.0 , V=1125.84 Space group: I-42D (122)

Lee Y , Hriljac J A , Vogt T , American Mineralogist , 90 (2005) p.247-251, Variable-temperature structural studies of tetranatrolite from Mt. Saint-Hilaire:, Synchrotron X-ray powder diffraction and Rietveld analysis, Sample: T = 200 C