data_global _chemical_name_mineral 'Schorl' loop_ _publ_author_name 'Grice J D' 'Ercit T S' _journal_name_full 'Neues Jahrbuch fur Mineralogie, Abhandlungen' _journal_volume 165 _journal_year 1993 _journal_page_first 245 _journal_page_last 266 _publ_section_title ; Ordering of Fe and Mg in the tourmaline crystal structure: The correct formula Sample: Schorl 2672 ; _database_code_amcsd 0018784 _chemical_compound_source 'Silver Crater, Hastings Co., Ontario, Canada' _chemical_formula_sum '(Na.99 Ca.01) Fe3.828 Mg1.269 V.021 Al3.42 Ti.402 Si6 B3 O31 H3.6' _cell_length_a 16.073 _cell_length_b 16.073 _cell_length_c 7.306 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 1634.573 _exptl_crystal_density_diffrn 3.294 _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 0.23010 0.99000 0.02670 CaX 0.00000 0.00000 0.23010 0.01000 0.02670 Fe2Y 0.12356 0.06178 0.63534 0.75600 0.00900 MgY 0.12356 0.06178 0.63534 0.23700 0.00900 VY 0.12356 0.06178 0.63534 0.00700 0.00900 AlZ 0.29853 0.26198 0.61195 0.57000 0.00610 Fe3Z 0.29853 0.26198 0.61195 0.26000 0.00610 MgZ 0.29853 0.26198 0.61195 0.09300 0.00610 TiZ 0.29853 0.26198 0.61195 0.06700 0.00610 SiT 0.19081 0.18917 0.00000 1.00000 0.00640 B 0.11010 0.22020 0.45540 1.00000 0.00920 O1 0.00000 0.00000 0.78000 1.00000 0.02020 O2 0.06145 0.12290 0.48440 1.00000 0.01080 O3 0.26580 0.13290 0.51220 1.00000 0.01380 O4 0.09252 0.18504 0.06860 1.00000 0.01130 O5 0.18348 0.09174 0.08750 1.00000 0.01100 O6 0.19557 0.18640 0.78060 1.00000 0.01010 O7 0.28323 0.28328 0.07830 1.00000 0.01090 O8 0.20850 0.26960 0.44220 1.00000 0.01240 H1 0.00000 0.00000 0.65500 0.60000 0.01000 H3 0.25400 0.12700 0.41600 1.00000 0.01000