AM_Tridymite_3 Formula: Si O2 Name: Tridymite Unit cell: 8.756 5.0108 8.2153 90.0 90.2825 90.0 , V=360.44 Space group: C1211 (1)

Graetsch H , Physics and Chemistry of Minerals , 28 (2001) p.313-321, X-ray powder diffraction study on the modulated high temperature forms, of SiO2 tridymite between 110 and 220 C, Sample: T = 150 C, Locality: synthetic