From Wikipedia, the free encyclopedia
Jump to: navigation, search

Ferropericlase or magnesiowüstite is a magnesium/iron oxide ((Mg,Fe)O) that is interpreted to be one of the main constituents of the Earth's lower mantle together with silicate perovskite, a magnesium/iron silicate with a perovskite structure. 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.[1]

Spin transition zone[edit]

Changes in the spin 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 X-ray spectroscopy. Results indicate that the change from a high to low spin state in iron occurs with increasing depth over a range from 1000 km to 2200 km.[2] The change in spin state is expected to be associated with a higher than expected increase in density with depth.

See also[edit]