Origin and cosmochemical implications of rubinite (Ca3Ti3+2Si3O12), a new CAI mineral from the Allende CV chondrite

Abstract

New minerals from chondritic refractory inclusions potentially record a specific history of the earliest stage of the solar system evolution. Rubinite (Ca₃Ti³⁺₂Si₃O₁₂) is a new garnet mineral identified in refractory inclusions from CV carbonaceous chondrites. Petrology and mineral chemistry of rubinite from the Allende CV chondrite suggest formation from a partial melt of a pre-existing nebula condensate under highly reduced conditions near the proto-Sun. Since mineralogical and petrological variations observed in Allende rubinite might reflect physicochemical conditions of both nebular and asteroidal processes, further investigation of the mineral will provide us new insights into the early solar system processes.