Eucrites

Eucrites are a group of basaltic achondrite meteorites that belong to the HED meteorite clan, which also includes Howardites and Diogenites. They are widely believed to originate from the crust of the asteroid 4 Vesta, making them among the best-preserved igneous rocks from the early solar system.

Mineralogy and textures characterize eucrites as mostly fine- to medium-grained basalts dominated by pyroxene (primarily pigeonite or augite) and plagioclase (labradorite to anorthite), with minor olivine, oxides, and metal. Many eucrites show igneous textures and reflect crystallization from basaltic magmas; some are brecciated, reflecting impact processes on Vesta.

Radiometric ages suggest crystallization of eucrite material very early in solar system history, roughly around 4.5 billion years ago. They are thought to have formed by fractional crystallization of basaltic magmas on Vesta's crust rather than being primitive meteorites from undifferentiated material.

Eucrites, together with diogenites and howardites, document the differentiation and thermal evolution of Vesta. Diogenites represent deeper orthopyroxene-rich rocks, while howardites are regolith breccias mixing eucrite and diogenite fragments. As a result, the Eucrite group provides key insights into early planetary crust formation and magmatism in the inner solar system.