University of Colorado

Mineral Structure and Property Data

Barite Group

The barite group is composed of the minerals barite (BaSO4), celestite (SrSO4), and anglesite (PbSO4).

The crystal structure of barite. 

                Barite      Celestite   Anglesite
                BaSO4       SrSO4        PbSO4


Form.Wt.        233.40      183.68      303.25  
Z               4           4           4       
CrystalSystem   Orth        Orth        Orth    
PointGroup      mmm         mmm         mmm     
SpaceGroup      Pbnm        Pbnm        Pbnm    

UnitCell
a(Å)            7.157       6.870       6.959
a(Å)            8.884       8.371       8.482
c(Å)            5.457       5.355       5.398
Vol(Å3)         346.97      307.96      318.62    

MolarVol        52.245      46.371      47.977
Density         4.467       3.961       6.321

Thermal Expansion(Volumetric)
alpha           63.7       
a0              0.6370
a1              0.0000 
a2              0.0000

Barite Group M Sites


End-Member         Celestite         Anglesite         Barite

C.N.               10                10                10
Occupant           Sr                Pb                Ba

Point Sym.         m                 m                 m
Wyckoff Not.       4c                4c                4c

Frac.Coord.
x                  .1583             .1667             .1585
y                  .1839             .1879             .1845
z                  1/4               1/4               1/4

Distances
Cation-Ox
O1(1)              2.536             2.613             2.770
O2(2)              2.980             3.005             3.075
O2(1)              2.636             2.619             2.798
O3(2)              2.690             2.648             2.811
O3(2)              2.653             2.737             2.811
O3(2)              2.816             2.910             2.911

Mean               2.745             2.783             2.879
sigma              .149             .159               .113

Poly.Vol.          45.90            47.97              52.99

Site Energy        -953.            -939.              -892.

Barite Group S Sites


End-Member         Celestite         Anglesite         Barite

C.N.               4                 4                 4
Occupant           S                 S                 S


Point Sym.         m                 m                 m
Wyckoff Not.       4c                4c                4c

Frac.Coord.
x                  .1853             .1842             .1911
y                  .4382             .4367             .4375
z                  1/4               1/4               1/4

Distances 
O1(1)              1.452             1.453             1.468
O2(1)              1.472             1.481             1.470
O3(2)              1.486             1.497             1.486

Mean               1.474             1.482             1.478
sigma              .016              .021              .010 

Poly.Vol.          1.643             1.669             1.655
Q.E.               1.0005            1.0012            1.0004
Ang.Var.           2.31              5.20              2.01

Site Energy        -9648.            -9590.            -9622.

Mineral Data Base Index

GEOL 1010 Syllabus

GEOL 3010 Syllabus

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