Fluoro-eckermannite Oberti R, Hawthorne F C, Camara F, Raudsepp M American Mineralogist 84 (1999) 102-111 Unusual M3+ cations in synthetic amphiboles with nominal fluoro-eckermannite composition: Deviations from stoichiometry and structural effects of the cummingtonite component Sample: V, Na.90Na.92Mg1.08Mg4.98V.02Si8O22F2 _database_code_amcsd 0002058 9.655 17.909 5.267 90 102.73 90 C2/m atom x y z occ Biso Si(1) .2844 .0848 .2816 .49 Si(2) .2924 .1706 .7861 .55 Mg(1) 0 .0887 .5 .64 V(2) 0 .1792 0 .01 .79 Mg(2) 0 .1792 0 .99 .79 Mg(3) 0 0 0 .61 Mg(4) 0 .2631 .5 .57 1.67 Na(4) 0 .2631 .5 .43 1.67 NaA 0 .5 0 .25 2.83 NaA(m) .0441 .5 .1026 .35 2.54 O1 .1139 .0847 .2134 .53 O2 .1207 .1696 .7209 .72 F3 .1041 0 .7068 .73 O4 .3689 .2483 .7830 1.45 O5 .3502 .1279 .0671 1.68 O6 .3474 .1189 .5678 2.25 O7 .3456 0 .2829 1.00