University of Colorado

Mineral Structure Data

Zircon Group

The silicate zircon group is composed of minerals of the general formula XSiO4 where X is a tetravalent cation Zr (zircon), Hf (hafnon), Th (thorite), or U (coffinite). There are also phosphate minerals with this structuure.

The crystal structure of zircon. 

End-Member      Zircon     Hafnon      Thorite     Coffinite
Formula         ZrSiO4      HfSiO4      ThSiO4      USiO4      


Form.Wt.        183.304    270.574     324.122     330.114
Z               4          4           4           4
CrystalSystem   Tetr       Tetr        Tetr        Tetr        
PointGroup      4mm        4mm         4mm         4mm
SpaceGroup      I41/amd     I41/amd     I41/amd     I41/amd

UnitCell
a(Å)            6.6042     6.5725      7.1328      6.995
c(Å)            5.9796     5.9632      6.3188      6.236   
Vol(Å3)         260.80      257.60      321.48      305.13

MolarVol        39.270     38.787      48.407      45.945
Density         4.668      6.976       6.696       7.185  

Thermal Expansion(Volumetric)
alpha           12.3

Elastic Properties
Ks(GPa)         227.9
G(Gpa)          109.0
Mineral Data Base Index

GEOL 1010 Syllabus

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