Articles | Volume 32, issue 1
Eur. J. Mineral., 32, 171–185, 2020
https://doi.org/10.5194/ejm-32-171-2020
Eur. J. Mineral., 32, 171–185, 2020
https://doi.org/10.5194/ejm-32-171-2020

Research article 11 Feb 2020

Research article | 11 Feb 2020

Breyite inclusions in diamond: experimental evidence for possible dual origin

Alan B. Woodland et al.

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Cited articles

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Short summary
We experimentally explored direct entrapment of breyite (CaSiO3) by diamond at upper-mantle conditions in a model subducted sediment rather than formation by retrogression of CaSiO3 perovskite, implying a deeper origin. Anhydrous low-T melting of CaCO3+SiO2 precludes breyite formation. Under hydrous conditions, reduction of melt results in graphite with breyite. Thus, breyite inclusions in natural diamond may form from aragonite + coesite or carbonate melt at 6–8 GPa via reduction with water.