Richterite Della Ventura G, Robert J-L, Raudsepp M, Hawthorne F C, Welch M D American Mineralogist 82 (1997) 291-301 Site occupancies in synthetic monoclinic amphiboles: Rietveld structure refinement and infrared spectroscopy of (nickel, magnesium, cobalt)-richterite Sample: Co80 _database_code_amcsd 0001884 9.9568 18.049 5.2742 90 104.413 90 C2/m atom x y z occ Si1 .2835 .0841 .2896 Si2 .2866 .1692 .8041 Mg1 0 .0889 .5 .18 Co1 0 .0889 .5 .82 Mg2 0 .1802 0 .28 Co2 0 .1802 0 .72 Mg3 0 0 0 .21 Co3 0 0 0 .79 Ca4 0 .2740 .5 .5 Na4 0 .2740 .5 .5 NaA 0 .4805 0 O1 .1136 .0872 .2163 O2 .1157 .1722 .7300 O3 .1099 0 .7000 O4 .3573 .2454 .7735 O5 .3487 .1274 .0918 O6 .3449 .1134 .5883 O7 .3467 0 .3055