AM_Dumortierite Formula: Si2.98 Al6.81 B O18 Name: Dumortierite Unit cell: 11.786 20.209 4.692 90.0 90.0 90.0 , V=1117.56 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: #2, BYU 12-5027, from Yuma Co., Arizona, USA