Bridgmanite
The most abundant mineral inside Earth, found and named only thanks to a shocked meteorite.
Key facts
- Formula
- (Mg,Fe)SiO3
- Family
- High-pressure minerals
- Crystal system
- Orthorhombic
- First described
- the Tenham L6 chondrite, 2014
Bridgmanite was described in 2014 from the Tenham meteorite, the first natural sample of the most abundant mineral in Earth. It is named after Percy Bridgman, who won the 1946 Nobel Prize in Physics for high-pressure research.
What it is
Bridgmanite is magnesium silicate with the perovskite structure, stable at pressures above about 24 gigapascals. It is thought to make up about 38% of Earth's volume, most of the lower mantle from 660 to 2,700 kilometres deep.
For decades it was known only from laboratory experiments, where it was called silicate perovskite. A mineral can be named only when a natural sample is studied, and it breaks down at Earth's surface, so no sample was available until it was found in a meteorite.
Where it is found
It survives as tiny grains in shock-melt veins of the Tenham L6 chondrite, where it crystallised and cooled so fast that it did not have time to change back. It has since been reported in a few other strongly shocked meteorites.
How it is recognised
Grains are smaller than a micrometre and are identified by synchrotron X-ray diffraction and electron microscopy.
Did you know?
The most common mineral on Earth was named only in 2014.
Bridgmanite in meteorites turns into glass under the electron beam used to study it, which made it very hard to identify.