University of Colorado

Mineral Structure Data

Zincite Group

The zincite group is composed of monoxide minerals of zinc (zincite ZnO) and beryllium (bromellite, BeO). Both Zn and Be show strong preference for tetrahedral coordination in oxygen minerals. Both of these minerals have the hexagonal wurtzite structure with the divalentcation in tetrahedral coordination with oxygen, and each oxygen in tetrahedral coordination to four divalent cations.

The crystal structure of zincite.

Zincite group unit cells.

EndMember        Zincite        Bromellite


Formula          ZnO            BeO
Form.Wt.         81.369         25.012
Density          5.712          3.080
Mol Volume       14.246         8.122

Z                2              2
Cryst.Sys.       Hexagonal      Hexagonal
                          
Cryst.Class      6mm        6mm
                           
Space Group        P63mc        P63mc

Cell Parameters
a                3.2427        2.6984
c                5.1948        4.2770

Vol.             47.306         26.970

Ref.             Sabine &        Sabine &
                 Hogg(1969)      Hogg (1969)



Thermal Expansion(Volumetric)
alpha         
a0  
a1 
a2 

Elastic Properties
Ks(GPa)        
G(Gpa)

Zincite Group Cation Sites

EndMember        Zincite        Bromellite



C.N.             4              4
Occupant         Zn             Be

Point Sym.       3m            3m
Wyckoff Not.     2b             2b

Frac.Coord.
x                1/3            1/3
y                2/3            2/3
z                0              0

Distances
O1(1)            1.988          1.619
O2(3)            1.969          1.642

Mean             1.974          1.636
sigma            .009           .011

Poly.Vol.        3.942          2.247
Q. E.            1.0006         1.0005
Ang. Var.        2.6            1.5

Site Energy      1105.          1333.

Mineral Data Base Index

GEOL 1010 Syllabus

GEOL 3010 Syllabus

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