data_global _chemical_name_mineral 'Dravite' loop_ _publ_author_name 'Hawthorne F C' 'MacDonald D J' 'Burns P C' _journal_name_full 'American Mineralogist' _journal_volume 78 _journal_year 1993 _journal_page_first 265 _journal_page_last 270 _publ_section_title ; Reassignment of cation site occupancies in tourmaline: Al-Mg disorder in the crystal structure of dravite ; _database_code_amcsd 0001551 _chemical_compound_source 'Osarar, Narok District, Kenya' _chemical_formula_sum 'Na.814 K.014 Ca.009 Ti.03 Cr.006 Fe.612 Mn.003 Mg2.274 Al6.078 Si6 B3 (O34 H4)' _cell_length_a 15.947 _cell_length_b 15.947 _cell_length_c 7.214 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 1588.783 _exptl_crystal_density_diffrn 3.211 _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 NaX 0.00000 0.00000 0.15920 0.81400 KX 0.00000 0.00000 0.15920 0.01400 CaX 0.00000 0.00000 0.15920 0.00900 TiY 0.93867 0.06133 0.56430 0.01000 CrY 0.93867 0.06133 0.56430 0.00200 FeY 0.93867 0.06133 0.56430 0.20400 MnY 0.93867 0.06133 0.56430 0.00100 MgY 0.93867 0.06133 0.56430 0.45000 AlY 0.93867 0.06133 0.56430 0.33400 AlZ 0.73849 0.70217 0.53860 0.84600 MgZ 0.73849 0.70217 0.53860 0.15400 SiT 0.81018 0.80835 0.92800 1.00000 B 0.11000 0.89000 0.38190 1.00000 O-H1 0.00000 0.00000 0.69890 1.00000 O2 0.06109 0.93891 0.41560 1.00000 O-H3 0.86947 0.13053 0.43810 1.00000 O4 0.09300 0.90601 0.99890 1.00000 O5 0.90733 0.09267 0.02120 1.00000 O6 0.81568 0.80578 0.70590 1.00000 O7 0.71512 0.71494 0.00590 1.00000 O8 0.73016 0.79077 0.36740 1.00000 loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 NaX 0.02270 0.02270 0.01770 0.01140 0.00000 0.00000 KX 0.02270 0.02270 0.01770 0.01140 0.00000 0.00000 CaX 0.02270 0.02270 0.01770 0.01140 0.00000 0.00000 TiY 0.00900 0.00900 0.01370 0.00300 0.00170 -0.00170 CrY 0.00900 0.00900 0.01370 0.00300 0.00170 -0.00170 FeY 0.00900 0.00900 0.01370 0.00300 0.00170 -0.00170 MnY 0.00900 0.00900 0.01370 0.00300 0.00170 -0.00170 MgY 0.00900 0.00900 0.01370 0.00300 0.00170 -0.00170 AlY 0.00900 0.00900 0.01370 0.00300 0.00170 -0.00170 AlZ 0.00730 0.00690 0.00690 0.00350 -0.00100 -0.00020 MgZ 0.00730 0.00690 0.00690 0.00350 -0.00100 -0.00020 SiT 0.00560 0.00540 0.00690 0.00250 0.00060 0.00040 B 0.00860 0.00860 0.00820 0.00450 0.00040 -0.00040 O-H1 0.01280 0.01280 0.01180 0.00640 0.00000 0.00000 O2 0.01380 0.01380 0.01220 0.00910 0.00050 -0.00050 O-H3 0.01390 0.01390 0.00710 0.00170 -0.00010 0.00010 O4 0.01010 0.01010 0.01150 0.00190 -0.00100 0.00100 O5 0.00970 0.00970 0.01060 0.00170 -0.00110 0.00110 O6 0.01190 0.01100 0.00740 0.00630 0.00120 0.00080 O7 0.00760 0.00860 0.01120 0.00220 0.00270 0.00210 O8 0.00980 0.00620 0.01590 0.00380 -0.00340 -0.00170