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 = 350 C
_database_code_amcsd 0006175
10.65448 10.65448 5.91703 90 90 120 P6_3/m
atom      x      y     z occ  Uiso
Ca1     1/3    2/3   .25     .0221
Ca2  .13372 .83245   .25     .0221
B     .2170  .7746   .75     .0113
Mn        0     .5     0     .0086
C         0      0 .0522  .5 .0113
O1   .09273  .4756   .25     .0342
O2   .31846  .9195   .75     .0342
O3   .30799  .4747 .5417     .0342
OC   .05851  .9157 .5642  .5 .0342