Ferropericlase or magnesio wüstite is a magnesium/ iron

oxide An oxide () is a chemical compound that contains at least one oxygen atom and one other element in its chemical formula. "Oxide" itself is the dianion of oxygen, an O2– (molecular) ion. with oxygen in the oxidation state of −2. Most of the E ...

with the chemical formula that is interpreted to be one of the main constituents of the Earth's

lower mantle The lower mantle, historically also known as the mesosphere, represents approximately 56% of Earth's total volume, and is the region from 660 to 2900 km below Earth's surface; between the transition zone and the outer core. The preliminar ...

together with the

silicate perovskite Silicate perovskite is either (the magnesium end-member is called bridgmanite) or (calcium silicate known as davemaoite) when arranged in a perovskite structure. Silicate perovskites are not stable at Earth's surface, and mainly exist in the low ...

(), a magnesium/iron

silicate In chemistry, a silicate is any member of a family of polyatomic anions consisting of silicon and oxygen, usually with the general formula , where . The family includes orthosilicate (), metasilicate (), and pyrosilicate (, ). The name is al ...

with a

perovskite structure A perovskite is any material with a crystal structure following the formula ABX3, which was first discovered as the mineral called perovskite, which consists of calcium titanium oxide (CaTiO3). The mineral was first discovered in the Ural mou ...

. Ferropericlase has been found as inclusions in a few natural diamonds. An unusually high iron content in one suite of diamonds has been associated with an origin from the lowermost mantle. Discrete ultralow-velocity zones in the deepest parts of the mantle, near the Earth's core, are thought to be blobs of ferropericlase, as seismic waves are significantly slowed as they pass through them, and ferropericlase is known to have this effect at the high pressures and temperatures found deep within the Earth's mantle. In May 2018, ferropericlase was shown to be anisotropic in specific ways in the high pressures of the lower mantle, and these anisotropies may help seismologists and geologists to confirm whether those ultra-low velocity zones are indeed ferropericlase, by passing seismic waves through them from various different directions and observing the exact amount of change in the velocity of those waves.

Spin transition zone

Changes in the

spin Spin or spinning most often refers to: * Spinning (textiles), the creation of yarn or thread by twisting fibers together, traditionally by hand spinning * Spin, the rotation of an object around a central axis * Spin (propaganda), an intentionally b ...

state of electrons in iron in mantle minerals has been studied experimentally in ferropericlase. Samples are subject to the conditions of the lower mantle in a laser-heated diamond anvil cell and the spin-state is measured using

synchrotron A synchrotron is a particular type of cyclic particle accelerator, descended from the cyclotron, in which the accelerating particle beam travels around a fixed closed-loop path. The magnetic field which bends the particle beam into its closed p ...

X-ray

spectroscopy Spectroscopy is the field of study that measures and interprets the electromagnetic spectra that result from the interaction between electromagnetic radiation and matter as a function of the wavelength or frequency of the radiation. Matter wa ...

. Results indicate that the change from a high to low

spin state Spin or spinning most often refers to: * Spinning (textiles), the creation of yarn or thread by twisting fibers together, traditionally by hand spinning * Spin, the rotation of an object around a central axis * Spin (propaganda), an intentionally b ...

in iron occurs with increasing depth over a range from 1000 km to 2200 km. The change in spin state is expected to be associated with a higher than expected increase in density with depth along with strong variations in viscosity.

Mantle abundance

Ferropericlase makes up about 20% of the volume of the

of the Earth, which makes it the second most abundant mineral phase in that region after silicate perovskite ; it also is the major host for iron in the lower mantle.Researchers locate mantle’s spin transition zone, leading to clues about earth’s structure
At the bottom of the transition zone of the mantle, the reaction : γ– transforms γ-olivine into a mixture of perovskite and ferropericlase and ''vice versa''. In the literature, this mineral phase of the lower mantle is also often called

magnesiowüstite Ferropericlase or magnesiowüstite is a magnesium/iron oxide with the chemical formula that is interpreted to be one of the main constituents of the Earth's lower mantle together with the silicate perovskite (), a magnesium/iron silicate with a ...

.Ferropericlase on Mindat.org
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References

Petrology Oxide minerals {{inorganic-compound-stub

Spin transition zone

Mantle abundance

See also

References