AM_Dumortierite_2 Formula: Si2.98 Al6.81 B.98 O18 Name: Dumortierite Unit cell: 11.8 20.222 4.699 90.0 90.0 90.0 , V=1121.27 Space group: PMCN (62)

Alexander V D , Griffen D T , Martin T J , American Mineralogist , 71 (1986) p.786-794, Crystal chemistry of some Fe- and Ti-poor dumortierites, Sample: #10, USNM 96698, from Petaca, New Mexco, USA