Physics and Chemistry of Minerals

, Volume 4, Issue 4, pp 317–339

Systematics of the spinel structure type


  • Roderick J. Hill
    • CSIRO Division of Mineral Chemistry
  • James R. Craig
    • Department of Geological SciencesVirginia Polytechnic Institute and State University
  • G. V. Gibbs
    • Department of Geological SciencesVirginia Polytechnic Institute and State University

DOI: 10.1007/BF00307535

Cite this article as:
Hill, R.J., Craig, J.R. & Gibbs, G.V. Phys Chem Minerals (1979) 4: 317. doi:10.1007/BF00307535


Systematic trends in the geometry of 149 oxide and 80 sulfide binary and ternary spinels have been examined from the standpoint of ionic radius and electronegativity. The mean ionic radii of the octahedral and tetrahedral cations, taken together, account for 96.9 and 90.5% of the variation in the unit cell parameter, a, of the oxides and sulfides, respectively, with the octahedral cation exerting by far the dominant influence in sulfides. The mean electronegativity of the octahedral cation exerts an additional, but small, influence on the cell edge of the sulfides. The equation a=(8/3√d)dtet+(8/3)doct, where dtet and doct are the tetrahedral and octahedral bond lengths obained from the sum of the ionic radii, accounts for 96.7 and 83.2% of the variation in a in the oxides and sulfides, respectively, again testifying to the applicability of the hard-sphere ionic model in the case of the spinel structure. Comparison of observed and calculated u values for 94 spinels indicates that up to 40% of the experimentally measured anion coordinates may be significantly in error. In addition to these compounds, u values are given for 52 spinels for which no data have previously been determined. Diagrams are presented for the rapid interpretation of the internal consistency of published data and the prediction of the structural parameters of hypothetical or partially studied spinels.

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© Springer-Verlag 1979