Northwest Africa 13765 (NWA 13765)

Boujdour, Morocco

Find: 2014

Classification: HED achondrite (Eucrite)

History: Purchased by Douglas Chenin from a Moroccan meteorite dealer in 2014. Reportedly found the same year at Jrifia near Boujdour, Morocco.

Physical characteristics: This meteorite is a single stone covered in black shiny fusion crust. Numerous fine cracks are present on the surface, small chipped spots reveal light tan colored interior. A freshly cut window shows a fine-grained texture with white feldspar grains and light gray pyroxene grains.

Petrography: (C. Agee, UNM) Electron microprobe analysis of a polished mount shows a mildly brecciated rock having clasts with variable grain size. The finest grained clasts have plagioclase and pyroxene in size range 50-200 μm. Coarser grained clasts show elongate plagioclase up to 500 μm and equant pyroxene 100-400 μm. Very fine exsolution lamellae are present in both low-Ca pyroxene and augite. Chromite, Fe-metal, silica, and ilmenite are ubiquitous accessory minerals.

Geochemistry: (C. Agee, UNM) Low-Ca pyroxene Fs_61.5±2.2Wo_3.0±1.2, Fe/Mn=31±2, n=10; augite Fs_27.3±0.5Wo_43.5±0.6, Fe/Mn=31±2, n=10; plagioclase An_88.9±0.8Ab_10.5±0.7Or_0.6±0.3, n=6. Compositionally uniform throughout with some grain size variation from clast to clast. Pyroxenes show nearly complete chemical compositional separation between low-Ca pyroxene and augite.

Classification: Monomict eucrite.

Specimens: 16.5 g on deposit at UNM, D. Chenin holds the main mass.