Gaudefroyite Antao S M, Hassan I The Canadian Mineralogist 46 (2008) 183-193 Gaudefroyite, Ca8Mn3+6[(BO3)6(CO3)2O6]: high-temperature crystal structure Locality: Wessels mine, Kalahari manganese field, South Africa Sample: T = 298 C _database_code_amcsd 0006174 10.64342 10.64342 5.91056 90 90 120 P6_3/m atom x y z occ Uiso Ca1 1/3 2/3 .25 .0199 Ca2 .1332 .8323 .25 .0199 B .2167 .7741 .75 .0097 Mn 0 .5 0 .0073 C 0 0 .0549 .5 .0097 O1 .0928 .4753 .25 .0318 O2 .3188 .9193 .75 .0318 O3 .3078 .4747 .5413 .0318 OC .0591 .9159 .5661 .5 .0318