Images
Formula: MgSiO3
High-pressure phase of MgSiO3, intermediate member of a solid-solution series
Environments
"Post-perovskite" is a confusing name for the high-pressure phase of MgSiO3 found in the lower part
of the Earth's Mantle. It is NOT a variety of perovskite,
CaTiO3, that occurs higher up in the Mantle, although it shares its structure.
Perovskite contains essential Ti; post-perovskite does not.
The name is derived from "perovskite-structured" MgSiO3, namely
bridgmanite, and "perovskite-structured" CaSiO3, namely
davemaoite. These minerals are not stable at the Earth's surface,
and mainly exist in the lower part of the Earth's Mantle. "Post-perovskite" is so named because it is formed
after these two "silicate perovskites". The low-pressure paramorph of
MgSiO3 that occurs near the surface of the Earth is enstatite
(Wiki).
Back to Minerals