AM_Grandidierite_6 Formula: (Mg.9 Fe.1) Al3 Si B O9 Name: Grandidierite Unit cell: 10.335 10.978 5.76 90.0 90.0 90.0 , V=653.52 Space group: PBNM (62)

Stephenson D A , Moore P B , Acta Crystallographica, Section B , 24 (1968) p.1518-1522, The crystal structure of grandidierite, (Mg,Fe)Al3SiBO9, Locality: Fort Dauphin, Madagascar