data_global
_chemical_name_mineral 'Tweddillite'
loop_
_publ_author_name
'Armbruster T'
'Gnos E'
'Dixon R'
'Gutzmer J'
'Hejny C'
'Dobelin N'
'Medenbach O'
_journal_name_full 'Mineralogical Magazine'
_journal_volume 66 
_journal_year 2002
_journal_page_first 137
_journal_page_last 150
_publ_section_title
;
 Manganvesuvianite and tweddillite, two new Mn3+-silicate minerals
 from the Kalahari manganese fields, South Africa
;
_database_code_amcsd 0014561
_chemical_compound_source 'Kalahari manganese fields, South Africa'
_chemical_formula_sum 'Ca Sr Al1.43 Mn1.313 Fe.257 Si3 O13 H'
_cell_length_a 8.934
_cell_length_b 5.718
_cell_length_c 10.325
_cell_angle_alpha 90
_cell_angle_beta 114.54
_cell_angle_gamma 90
_cell_volume 479.805
_exptl_crystal_density_diffrn      3.779
_symmetry_space_group_name_H-M 'P 1 21/m 1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'x,1/2-y,z'
  '-x,1/2+y,-z'
  '-x,-y,-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
CaA1   0.76460   0.75000   0.15750   1.00000   0.01165
SrA2   0.59410   0.75000   0.42163   1.00000   0.01305
AlM1   0.00000   0.00000   0.00000   0.43000   0.00811
Mn3+M1   0.00000   0.00000   0.00000   0.48000   0.00811
Fe3+M1   0.00000   0.00000   0.00000   0.09000   0.00811
AlM2   0.00000   0.00000   0.50000   1.00000   0.00836
Mn3+M3   0.29540   0.25000   0.21810   0.83333   0.01140
Fe3+M3   0.29540   0.25000   0.21810   0.16667   0.01140
Si1   0.34170   0.75000   0.04110   1.00000   0.01203
Si2   0.68770   0.25000   0.27870   1.00000   0.01077
Si3   0.18030   0.75000   0.31500   1.00000   0.01089
O1   0.23890   0.99150   0.03860   1.00000   0.01798
O2   0.29840   0.97860   0.34800   1.00000   0.01444
O3   0.79670   0.01600   0.34330   1.00000   0.01482
O4   0.06000   0.25000   0.13120   1.00000   0.01140
O5   0.03690   0.75000   0.14790   1.00000   0.01267
O6   0.06610   0.75000   0.40610   1.00000   0.01267
O7   0.51740   0.75000   0.16910   1.00000   0.01773
O8   0.52770   0.25000   0.31100   1.00000   0.01267
O9   0.63230   0.25000   0.10630   1.00000   0.02280
O10   0.08150   0.25000   0.42930   1.00000   0.01140
H10   0.06000   0.25000   0.33900   1.00000   0.05003