Pyroxferroite: Stability and X-ray Crystallography of Synthetic Ca _0.15 Fe _0.85 SiO ₃ Pyroxenoid

Abstract

Synthetic Ca(0.15)Fe(0.85)SiO(3) pyroxenoid has the same (pyroxmangite) structure and very nearly the same composition as pyroxferroite, a new mineral found in Apollo 11 lunar samples. The synthetic material is not stable below pressures of approximately 10 kilobars. It appears likely that the lunar pyroxferroite has persisted in a metastable state for some billions of years.