Work

Synthesis of K- and Fe-rich davemaoite

Year: 2026

Type: article

Abstract: The type material of davemaoite, CaSiO3-perovskite, contains several atomic% of Fe, Al, Na, and K, which has potential implications for the distribution of alkaline elements and the Urey number of the deep mantle. Previous experiments have not shown such high alkaline contents in davemaoite, and it was questioned whether the type material actually formed in the deep mantle. However, these studies did not explore compositions similar to that material. We show that glass of a composition close to that of type davemaoite transforms to a homogeneous perovskite phase at 22 GPa. This finding supports the correlation of Na+K with Ca and ferric iron in deep mantle rock. The perovskite-type solid solution is volumetrically favored by ∼2% over a mixture of calcium-ferrite type oxides and end-member davemaoite.

Source: American Mineralogist

DOI: 10.2138/am-2026-10284