Fluor-buergerite Grice J D, Ercit T S Neues Jahrbuch fur Mineralogie, Abhandlungen 165 (1993) 245-266 Ordering of Fe and Mg in the tourmaline crystal structure: The correct formula Sample: Buergerite 43293 Locality: Mapimi, Durango, Mexico _database_code_amcsd 0018787 15.874 15.874 7.196 90 90 120 R3m atom x y z occ Uiso NaX 0 0 .2154 .88 .0242 CaX 0 0 .2154 .04 .0242 Fe3Y .13246 .06623 .6223 .55 .0119 AlY .13246 .06623 .6223 .3033 .0119 Fe2Y .13246 .06623 .6223 .1267 .0119 MgY .13246 .06623 .6223 .02 .0119 AlZ .29865 .25865 .6044 .9167 .0067 FeZ .29865 .25865 .6044 .0833 .0067 SiT .19151 .19048 0 .9717 .0054 BT .19151 .19048 0 .0167 .0054 TiT .19151 .19048 0 .0117 .0054 B .1101 .2202 .4523 .0075 F1 0 0 .7681 .74 .0181 O1 0 0 .7681 .26 .0181 O2 .06047 .12094 .4863 .0090 O3 .26358 .13179 .5205 .55 .0090 OH3 .26358 .13179 .5205 .45 .0090 O4 .09452 .18904 .0754 .0094 O5 .18232 .09116 .0846 .0101 O6 .1928 .1865 .7751 .0081 O7 .2868 .2860 .0750 .0077 O8 .2095 .2700 .4385 .0077