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 = 960 m _database_code_amcsd 0004074 8.0882 8.0882 8.0882 90 90 90 *Fd3m .125 .125 .125 atom x y z occ MgT .125 .125 .125 .800 AlT .125 .125 .125 .200 AlM .5 .5 .5 .785 MgM .5 .5 .5 .200 Cr3+M .5 .5 .5 .015 O .26258 .26258 .26258