data_9000743
_chemical_name 'Biotite'
loop_
_publ_author_name
'Bohlen S R'
'Peacor D R'
'Essene E J'
_journal_name_full "American Mineralogist"
_journal_volume 65
_journal_year 1980
_journal_page_first 55
_journal_page_last 62
_publ_section_title
;
 Crystal chemistry of a metamorphic biotite and its significance in water
 barometry
 from Au Sable Forks, New York
;
_chemical_formula_sum 'K Fe1.392 Mg1.161 Ti.276 (Si2.792 Al1.208) O12'
_cell_length_a 5.357
_cell_length_b 9.245
_cell_length_c 20.234
_cell_angle_alpha 90
_cell_angle_beta 94.978
_cell_angle_gamma 90
_cell_volume 998.318
_symmetry_space_group_name_H-M 'C 1 2/c 1'
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '1/2+x,1/2+y,z'
  'x,-y,1/2+z'
  '1/2+x,1/2-y,1/2+z'
  '-x,y,1/2-z'
  '1/2-x,1/2+y,1/2-z'
  '-x,-y,-z'
  '1/2-x,1/2-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
K   0.00000   0.08440   0.25000   1.00000
Fe1   0.75000   0.25000   0.00000   0.46400
Mg1   0.75000   0.25000   0.00000   0.38700
Ti1   0.75000   0.25000   0.00000   0.09200
Fe2   0.24800   0.08260   0.00000   0.46400
Mg2   0.24800   0.08260   0.00000   0.38700
Ti2   0.24800   0.08620   0.00000   0.09200
Si1   0.46250   0.25080   0.13730   0.69800
Al1   0.46250   0.25080   0.13730   0.30200
Si2   0.96300   0.41750   0.13750   0.69800
Al2   0.96300   0.41750   0.13750   0.30200
O1   0.73410   0.32010   0.16560   1.00000
O2   0.23680   0.34760   0.16590   1.00000
O3   0.44590   0.08360   0.16600   1.00000
O4   0.43230   0.23950   0.05440   1.00000
O5   0.93610   0.40730   0.05450   1.00000
O6   0.93670   0.07090   0.05370   1.00000