Northwest Africa 1648

Morocco

Purchased 2002 October

Achondrite (diogenite, polymict)

A complete fusion-crusted stone (803 g) was purchased from a Moroccan dealer by A. and G. Hupé (xHupé). Classification and mineralogy (A. Irving and S. Kuehner, UWS): Heterogeneous breccia composed of multiple clast types of varying size. Angular mineral clasts are predominantly orthopyroxene with subordinate anorthite (Ab5), silica, exsolved pigeonite, ilmenite and troilite. The orthopyroxene clasts are homogeneous and have low Ca contents, but range widely in Fe/Mg ratio (FeO = 12.6–22.5 wt%, FeO/MnO = 28.2–34.8), suggesting multiple diogenitic parent rocks. Sparse polycrystalline clasts include cumulate eucrites, basaltic eucrites, a quench-textured clast consisting of dendritic olivine grains in glass, and fine grained ferroan inter-growths (breakdown of former pyroxferroite) composed of hedenbergite + fayalite + silica ± ilmenite ± troilite attached to anorthite laths. Breccia consisting of various diogenites (>80% by volume), sparse cumulate eucrites and rare basaltic eucrites. Specimens: type specimen, 22 g, and thin section, UWS; main mass, xHupé.