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Synthetic armalcolite and pseudobrookite

Published online by Cambridge University Press:  05 July 2018

A. Ya. Medvedev*
Affiliation:
Institute of Geochemistry, PB. 4019, 664033 Irkutsk, Russia

Abstract

Armalcolite and pseudobrookite have been crystallized from synthetic melts of basaltic composition with variable amounts of added TiO2. It was found that the composition of the armalcolite and pseudobrookite are dependent on the TiO2 content of the melt and the conditions (particularly oxygen fugacity, but also temperature and quenching rate) of formation. The maximum Al2O3 content of pseudobrookite appears to be ∼14–15 wt.% Al2O3, a spinel-like phase being exsolved at higher Al2O3 concentrations. Generally armalcolite is formed at low pO2 and pseudobrookite at higher oxygen fugacities.

Type
Mineralogy
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1996

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