O Neill H St C , Dollase W A , Physics and Chemistry of Minerals , 20 (1994) p.541-555, Crystal structures and cation distributions in simple spinels from powder XRD, structural refinements: MgCr2O4, ZnCr2O4, Fe3O4 and the temperature dependence, of the cation distribution in ZnAl2O4, Sample: ZnCr2O4, BGI (Mo radiation)