Post-Oxide Phases of Forsterite and Enstatite
- Thomas J. Shankland and
- Jay D. Bass
Published Online: 21 MAR 2013
Copyright 1988 by the American Geophysical Union.
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
- Published Online: 21 MAR 2013
- Published Print: 1 JAN 1988
Print ISBN: 9780875902401
Online ISBN: 9781118664971
- Magnesian orthosilicate (Mg2SiO4);
- Metasilicate (MgSiO3);
- X-ray diffraction data
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.