Post-Oxide Phases of Forsterite and Enstatite

  1. Thomas J. Shankland and
  2. Jay D. Bass
  1. Lin-Gun Liu

Published Online: 21 MAR 2013

DOI: 10.1029/SP026p0358

Elastic Properties and Equations of State

Elastic Properties and Equations of State

How to Cite

Liu, L.-G. (1988) Post-Oxide Phases of Forsterite and Enstatite, in Elastic Properties and Equations of State (eds T. J. Shankland and J. D. Bass), American Geophysical Union, Washington, D. C.. doi: 10.1029/SP026p0358

Author Information

  1. Research School of Earth Sciences, Australian National University, Canberra, Australia

Publication History

  1. Published Online: 21 MAR 2013
  2. Published Print: 1 JAN 1988

ISBN Information

Print ISBN: 9780875902401

Online ISBN: 9781118664971

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Keywords:

  • Enstatite;
  • Forsterite;
  • Magnesian orthosilicate (Mg2SiO4);
  • Metasilicate (MgSiO3);
  • X-ray diffraction data

Summary

Both forsterite (Mg2SiO4) and enstatite (MgSiO3) enter a post-oxide phase characterized by the orthorhombic perovskite structure when subjected to high pressure and temperature in the diamond-anvil press coupled with laser heating. The lattice parameters for the perovskite phase of MgSiO3 are ao = 4.790 ± 0.002, bo = 4.943 ± 0.002, and co = 6.897 ± 0.003 Å with Z = 4. The calculated density of MgSiO3 (perovskite) is thus 4.083 g/cm3, or 2.8% denser than its isochemical mixed oxides with rocksalt and rutile structures. The density of a mixture of MgSiO3 (perovskite)plus MgO (periclase) is 1.9% greater than that of the mixed oxides with the forsterite stoichiometry.