AM_Omphacite_5 Formula: (Fe.475 Al.525) (Ca.492 Na.508) Si2 O6 Name: Omphacite Unit cell: 9.622 8.826 5.279 90.0 106.92 90.0 , V=428.91 Space group: P12/N1 (13)

Curtis L , Gittins J , Kocman V , Rucklidge J C , Hawthorne F C , Ferguson R B , The Canadian Mineralogist , 13 (1975) p.62-67, Two crystal structure refinements of a P2/n titanian ferro-omphacite, Sample: Tronto