Report

Ferric Iron Content of Mineral Inclusions in Diamonds from São Luiz: A View into the Lower Mantle

See allHide authors and affiliations

Science  17 Oct 1997:
Vol. 278, Issue 5337, pp. 434-436
DOI: 10.1126/science.278.5337.434

You are currently viewing the abstract.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

Abstract

Mössbauer spectroscopy on inclusions in diamonds from São Luiz, Brazil, show that (Mg,Fe)O inclusions contain little Fe3+ (Fe3+/ΣFe ≤ 7%), whereas inclusions with pyroxene composition (believed to have been originally in the perovskite structure) and tetragonal almandine-pyrope phase (TAPP) inclusions contain high relative amounts of Fe3+ (Fe3+/ΣFe = 20 to 75%). These observations are consistent with high-pressure experiments on synthetic samples and support the idea that the inclusions originated in the lower mantle. Fe-Mg partitioning data for co-existing (Mg,Fe,Al)(Si,Al)O3 – (Mg,Fe)O pairs also indicate that the phases were in equilibrium at the time of diamond formation in the lower mantle.

View Full Text