Group of minerals found in the CAIs of meteorites such as CV chondrites. Melilite consists almost exclusively of the binary solid solution gehlenite (Ca2Al2SiO7) – åkermanite (Ca2MgSi2O7). The melilite in CAIs is closer to gehlenite in composition. The first-formed (highest-temperature) melilite crystallizing from a melt is relatively aluminum-rich and becomes progressively magnesium-rich with falling temperature. This is the compositional region of interest for most CAIs (except forsterite-bearing type-B CAIs), and the expected result for an igneous melilite in this range (such as those in type Bs) is a compositionally zoned crystal having an aluminum-rich core and magnesium-rich rim.

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