AM_Gonnardite_1
Formula: (Si2.85 Al2.15) O12.72 (Na1.7 Ca.3) H8
Name: Gonnardite
Unit cell: 13.197 13.197 6.63 90.0 90.0 90.0 , V=1154.69
Space group: I-42D (122)

Evans H T , Konnert J A , Ross M , American Mineralogist , 85 (2000) p.1808-1815, The crystal structure of tetranatrolite from Mont Saint-Hilaire, Quebec, and its, chemical and structural relationship to paranatrolite and gonnardite