Bridgmanite: New Name For the Earth's Most Abundant Mineral
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| This image shows a fragment of the 4.5 billion-year-old Tenham meteorite that contains tiny crystals of bridgmanite. Image credit: Chi Ma. |
Bridgmanite is a high-pressure mineral, also known as magnesium iron
silicate (Mg,Fe)SiO₃ part of the perovskite family, and is the most abundant mineral in the
Earth's lower mantle. It was named after the physicist Percy Bridgman,
who won the Nobel Prize for his work on high-pressure physics.
Bridgmanite is significant because it makes up a large portion of the
Earth's interior, and understanding its properties helps scientists
learn more about the deep Earth and the processes that drive plate
tectonics and volcanism.
Although synthetic examples of this mineral have been well studied, no naturally occurring samples had ever been found in a rock on the planet’s surface.
Thanks to the work of mineralogists Dr Chi Ma from California Institute of Technology and Prof Oliver Tschauner from the University of Nevada-Las Vegas, naturally occurring (Mg,Fe)SiO₃-perovskite has been found in the Tenham meteorite – a fragment of a larger, 4.5 billion-year-old meteorite that fell in Queensland, Australia, in 1879.
Because the Tenham meteorite had survived high-energy collisions with asteroids in space, parts of it were believed to have experienced the high-pressure conditions found in the Earth’s mantle. That, scientists thought, made it a good candidate for containing (Mg,Fe)SiO₃-perovskite, now simply called bridgmanite.
The scientists used synchrotron X-ray diffraction mapping to find indications of the bridgmanite. They then examined the mineral and its surroundings with a high-resolution scanning electron microscope and determined the composition of the tiny bridgmanite crystals using an electron microprobe.
In March 2014, the team submitted a proposal to the International Mineralogical Association Commission on New Minerals, Nomenclature and Classification (CNMNC) with the suggested name of bridgmanite. CNMNC approved the mineral and its name.
“It is a really cool discovery. Our finding of natural bridgmanite not only provides new information on shock conditions and impact processes on small bodies in the solar system, but the tiny bridgmanite found in a meteorite could also help investigations of phase transformation mechanisms in the deep Earth,” Dr Ma said.
The study was published in the journal Science.
Although synthetic examples of this mineral have been well studied, no naturally occurring samples had ever been found in a rock on the planet’s surface.
Thanks to the work of mineralogists Dr Chi Ma from California Institute of Technology and Prof Oliver Tschauner from the University of Nevada-Las Vegas, naturally occurring (Mg,Fe)SiO₃-perovskite has been found in the Tenham meteorite – a fragment of a larger, 4.5 billion-year-old meteorite that fell in Queensland, Australia, in 1879.
Because the Tenham meteorite had survived high-energy collisions with asteroids in space, parts of it were believed to have experienced the high-pressure conditions found in the Earth’s mantle. That, scientists thought, made it a good candidate for containing (Mg,Fe)SiO₃-perovskite, now simply called bridgmanite.
The scientists used synchrotron X-ray diffraction mapping to find indications of the bridgmanite. They then examined the mineral and its surroundings with a high-resolution scanning electron microscope and determined the composition of the tiny bridgmanite crystals using an electron microprobe.
In March 2014, the team submitted a proposal to the International Mineralogical Association Commission on New Minerals, Nomenclature and Classification (CNMNC) with the suggested name of bridgmanite. CNMNC approved the mineral and its name.
“It is a really cool discovery. Our finding of natural bridgmanite not only provides new information on shock conditions and impact processes on small bodies in the solar system, but the tiny bridgmanite found in a meteorite could also help investigations of phase transformation mechanisms in the deep Earth,” Dr Ma said.
The study was published in the journal Science.
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