AM_Gonnardite_2 Formula: (Si2.685 Al2.315) O12.74 Na1.462 Ca.474 H8 Name: Gonnardite Unit cell: 13.1988 13.1988 6.6288 90.0 90.0 90.0 , V=1154.79 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: at ambient conditions