The first known natural occurrence of calcium monoaluminate, in a calcium-aluminum-rich inclusion from the CH chondrite Northwest Africa 470

M. A. Ivanova, M. I. Petaev, G. J. MacPherson, M. A. Nazarov, L. A. Taylor, J. A. Wood

Abstract


Natural calcium monoaluminate, CaA12O4, has been found in a grossite-rich calcium-aluminum-rich inclusion (CAI) from the CH chondrite Northwest Africa 470. The calcium monoaluminate occurs as coloress ~10 μm subhedral grains intergrown with grossite, perovskite, and melilite. Nebular condensation is the most likely origin for the precursor matrials of this CAI, but calculations suggest that dust/gas ratios substantially enhanced over solar are required to stabilize CaA12O4.

Keywords


calcium-aluminum-rich inclusion (CAI);Northwest Africa 470;Nebular condensation

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