Spinel (predominantly the MgAl 2 O 4 -end member)-bearing crustal lithologies have long been recognized in the Apollo sample collection. However, such lithologies are rather rare and individual samples are small in mass (<1 g). It has been inferred since the early 1970s that these lithologies (e.g., extensively shocked spinel ± cordierite troctolite clasts) were excavated during basin-forming events from the deep lunar crust and/or upper mantle

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Northwest Africa (NWA) 8686 is an olivine‐phyric shergottite containing up to ~500 μm long olivine crystals in a fine‐grained groundmass of augite, pigeonite, and maskelynite, with accessory merrillite, pyrrhotite, and oxides. Bulk rock and mineral major and trace element concentrations are reported for NWA 8686, along with bulk rock highly siderophile element (HSE: Os, Ir, Ru, Pt, Pd, Re) abundances and 187Re‐187Os data. Based on its mineralogy, texture, and bulk rock rare earth element (REE) abundances, NWA 8686 is classified as an intermediate olivine‐phyric shergottite. It is notable for having some of the most ferroan olivine macrocrysts (forsterite content = 51.5 ± 3.5) of any olivine‐phyric shergottite. Olivine is absent from the NWA 8686 groundmass, which is unique for olivine‐phyric shergottites, and the calculated groundmass composition is also not olivine normative. The bulk meteorite has a low Mg# of 59 yet has HSE in broadly chondritic proportions (~0.005 × CI chondrite). The bulk rock REE pattern for NWA 8686 shows depletions in both the light and heavy REE relative to the middle REE. Compiled olivine and bulk rock data for olivine‐phyric shergottites indicate that olivine macrocrysts in almost all these meteorites are the result of entrainment of antecrysts or xenocrysts. The combination of low Mg# and chondritic HSE signatures in NWA 8686 means that it may have been formed either from the mixing between an evolved lava and early‐formed HSE‐rich phases such as Os‐Ir alloys or by the melting of a low Mg# mantle source with chondritic HSE abundances. The elevated Gd/Yb ratio in both NWA 8686 and other intermediate olivine‐phyric shergottites indicates that garnet was involved as either a residual or fractionating phase in their petrogenesis.

Mantles of rocky planets are dominantly composed of olivine and its high-pressure polymorphs, according to seismic data of Earth’s interior, the mineralogy of natural samples, and modelling results. The missing mantle problem represents the paucity of olivine-rich material among meteorite samples and remote observation of asteroids, given how common differentiated planetesimals were in the early Solar System. Here we report the discovery of new olivine-rich meteorites that have asteroidal origins and are related to V-type asteroids or vestoids. Northwest Africa 12217, 12319, and 12562 are dunites and lherzolite cumulates that have siderophile element abundances consistent with origins on highly differentiated asteroidal bodies that experienced core formation, and with trace element and oxygen and chromium isotopic compositions associated with the howardite-eucrite-diogenite meteorites. These meteorites represent a step towards the end of the shortage of olivine-rich material, allowing for full examination of differentiation processes acting on planetesimals in the earliest epoch of the Solar System.