Raman spectroscopic study of inclusions of ferropericlase and other minerals from super-deep diamonds

Twenty-two inclusions of ferropericlase from thirteen lower-mantle diamonds, collected in the Rio Sorriso placer deposit in the Juina area, Mato Grosso State, Brazil, were studied using Raman spectroscopy. Pure periclase (MgO) and pure wüstite (FeO) with NaCl-type structure are inactive in first-order Raman scattering. However, natural ferropericlase are characterized by broad compositional variations in terms of the contents of Fe 2+ , Fe 3+ , Ni 2+ and other minor elements, so that their Raman