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 = 196 C _database_code_amcsd 0006172 10.62601 10.62601 5.90008 90 90 120 P6_3/m atom x y z occ Uiso Ca1 1/3 2/3 .25 .0158 Ca2 .1325 .8322 .25 .0158 B .2178 .7740 .75 .0057 Mn 0 .5 0 .0049 C 0 0 .0565 .5 .0057 O1 .0926 .4744 .25 .0288 O2 .3198 .9196 .75 .0288 O3 .3083 .4753 .5406 .0288 OC .0593 .9152 .5680 .5 .0288