data_global _chemical_name_mineral 'Chromium-dravite' loop_ _publ_author_name 'Bosi F' 'Lucchesi S' 'Reznitskii L' _journal_name_full 'European Journal of Mineralogy' _journal_volume 16 _journal_year 2004 _journal_page_first 345 _journal_page_last 352 _publ_section_title ; Crystal chemistry of the dravite-chromdravite series Note: Tourmaline TM1p43e ; _database_code_amcsd 0007061 _chemical_compound_source 'Sludyanka crystalline complex, Lake Baikal, Russia' _chemical_formula_sum 'Na.888 Ca.028 K.022 Cr3.15 Mg2.169 Al3.354 V.279 Zn.015 Ti.003 Fe.036 Si5.988 B3 O30.741 F.259 H3.034' _cell_length_a 15.9911 _cell_length_b 15.9911 _cell_length_c 7.2764 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 1611.402 _exptl_crystal_density_diffrn 3.237 _symmetry_space_group_name_H-M 'R 3 m' loop_ _space_group_symop_operation_xyz 'x,y,z' '2/3+x,1/3+y,1/3+z' '1/3+x,2/3+y,2/3+z' 'x,x-y,z' '2/3+x,1/3+x-y,1/3+z' '1/3+x,2/3+x-y,2/3+z' '-y,-x,z' '2/3-y,1/3-x,1/3+z' '1/3-y,2/3-x,2/3+z' '-x+y,y,z' '2/3-x+y,1/3+y,1/3+z' '1/3-x+y,2/3+y,2/3+z' '-y,x-y,z' '2/3-y,1/3+x-y,1/3+z' '1/3-y,2/3+x-y,2/3+z' '-x+y,-x,z' '2/3-x+y,1/3-x,1/3+z' '1/3-x+y,2/3-x,2/3+z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy _atom_site_U_iso_or_equiv NaX 0.00000 0.00000 0.22450 0.88800 0.01800 CaX 0.00000 0.00000 0.22450 0.02800 0.01800 KX 0.00000 0.00000 0.22450 0.02200 0.01800 CrY 0.12349 0.06174 0.63680 0.72600 0.00450 MgY 0.12349 0.06174 0.63680 0.21700 0.00450 AlY 0.12349 0.06174 0.63680 0.03200 0.00450 V3+Y 0.12349 0.06174 0.63680 0.01900 0.00450 ZnY 0.12349 0.06174 0.63680 0.00500 0.00450 Ti4+Y 0.12349 0.06174 0.63680 0.00100 0.00450 AlZ 0.29794 0.26194 0.60929 0.54100 0.00540 MgZ 0.29794 0.26194 0.60929 0.25300 0.00540 CrZ 0.29794 0.26194 0.60929 0.16200 0.00540 V3+Z 0.29794 0.26194 0.60929 0.03700 0.00540 Fe2+Z 0.29794 0.26194 0.60929 0.00600 0.00540 SiT 0.19050 0.18872 0.00000 0.99800 0.00440 AlT 0.19050 0.18872 0.00000 0.00200 0.00440 B 0.11011 0.22022 0.45410 1.00000 0.00470 O1W 0.00000 0.00000 0.76530 0.70700 0.00640 F1W 0.00000 0.00000 0.76530 0.25900 0.00640 O-H1W 0.00000 0.00000 0.76530 0.03400 0.00640 O2 0.06044 0.12088 0.48830 1.00000 0.00670 O3V 0.25770 0.12885 0.50990 1.00000 0.01000 O4 0.09270 0.18540 0.07160 1.00000 0.00980 O5 0.18320 0.09160 0.09160 1.00000 0.00870 O6 0.19234 0.18293 0.77910 1.00000 0.00700 O7 0.28368 0.28345 0.07440 1.00000 0.00890 O8 0.20809 0.26881 0.43840 1.00000 0.01010 H3V 0.25200 0.12600 0.38000 1.00000 0.15000