Grandidierite Stephenson D A, Moore P B Acta Crystallographica B24 (1968) 1518-1522 The crystal structure of grandidierite, (Mg,Fe)Al3SiBO9 Locality: Fort Dauphin, Madagascar _database_code_amcsd 0009346 10.335 10.978 5.760 90 90 90 Pbnm atom x y z occ Biso Mg .0933 .2188 .25 .90 .53 Fe .0933 .2188 .25 .10 .53 All 0 0 0 .39 Al2 .5 0 0 .39 Al3 .2262 .4478 .25 .33 Si .4339 .2633 .25 .27 B .2508 .0003 .75 .30 O1 .2760 .2881 .25 .35 O2 .1187 .0218 .25 .62 O3 .1217 -.0036 .75 .57 O4 .4737 .1211 .25 .33 O5 .5460 .0992 .75 .47 O6 -.0077 .1703 -.0239 .53 O7 .1804 .5019 -.0462 .62