Meteorite type CLASS / OFFICIAL NAME or NUMBER (Meteoritical Bulletin Database): NWA 17660 - HED Achondrite - Eucrite Polymict FALL/FIND LOCATION: North West Africa WEIGHT: 153.81 grams half stone Size: 7 cm x 4 cm x 3.9 cm Meteoritical Bulletin Database entry: NWA 17660 Eucrite Polymict Writeup from Meteoritical Bulletin Database: Northwest Africa 17660 (NWA 17660) (Northwest Africa) Purchased: 2024 Sep Classification: HED achondrite (Eucrite, polymict) History: Purchased by Juan Aviles Poblador in September 2024 from a dealer in Erfoud, Morocco. Petrography: (A. Irving, UWS, and P. Carpenter, WUSL) Complex breccia composed of angular mineral clasts, some fine- to medium-grained lithic clasts with subophitic to intergranular textures, and ~10 vol.% distributed rounded lithic breccia clasts in a fine grained fragmental matrix. The major minerals are exsolved pigeonite, unexsolved pigeonite, calcic plagioclase, subcalcic augite and augite. Minor constituents are diogenitic orthopyroxene (~5 vol.%), silica polymorph, Ilmenite, low-Ti chromite, troilite, fayalite, merrillite, zircon and kamacite. The unusual rounded lithic breccia clasts consist of sparse angular fragments of many of those same mineral phases within an ultra-fine grained opaque to isotropic, microcrystalline to glassy, aluminous matrix (deep sepia brown in thin section), which may represent a quenched melt. Several thin cross-cutting shock melt veinlets are present in the studied thin section. Geochemistry: Low-Ca pyroxene (Fs64.3Wo2.8; Fs55.5Wo3.3; FeO/MnO = 32-33, N = 2), pigeonite (Fs37.0-40.2Wo6.7-8.0, FeO/MnO = 31-34, N = 2), subcalcic augite (Fs34.3Wo31.9, FeO/MnO = 30), augite (Fs29.4Wo43.0, FeO/MnO = 35), diogenitic orthopyroxene (Fs29.8-31.3Wo4.9-4.4, FeO/MnO = 28-29, N = 2), plagioclase (An79.6-91.8Or1.4-0.2, N = 4), fayalite (Fa75.9-77.8, FeO/MnO = 43-44, N =2), matrix of (?)regolithic breccia clasts with aluminous subcalcic augite bulk composition (Fs43.5Wo29.0, FeO/MnO = 34, Al2O3 13.1 wt.%). Classification: Eucrite (polymict breccia). This specimen is unusual because of its significant content of eucritic breccia clasts with a microcrystalline to glassy aluminous matrix, which may signify a regolithic component. Specimens: 27.6 g including one polished thin section at UWB; remainder with Mr. Juan Aviles Poblador. I am a member of the Meteoritical Society (#7743) and have been collecting meteorites for over 15 years.