Spinel Princivalle F, Martignago F, Dal Negro A American Mineralogist 91 (2006) 313-318 Kinetics of cation ordering in natural Mg(Al,Cr3+)2O4 spinels Locality: Olkhon metamorphic complex, Lake Baikal, Russia Sample: Ch, annealed at T = 650 C, ordering, t = 0 m _database_code_amcsd 0004068 8.0865 8.0865 8.0865 90 90 90 *Fd3m .125 .125 .125 atom x y z occ MgT .125 .125 .125 .729 AlT .125 .125 .125 .271 AlM .5 .5 .5 .714 MgM .5 .5 .5 .271 Cr3+M .5 .5 .5 .015 O .26164 .26164 .26164