Northwest Africa 11116 (NWA 11116)

(Northwest Africa)

Purchased: 2016

Classification: HED achondrite (Eucrite, monomict)

History: Two stones weighing 875.4 and 163.7 g were found and subsequently purchased in Morocco in 2015. J. Donald Cline and John Sinclair acquired the samples from a meteorite prospector at the Tucson Gem and Mineral Show in February of 2016.

Physical characteristics: Sample is irregularly shaped, with a pitted surface (similar to a regmaglypted surface). Sample lacks fusion crust. The sample is mottled brownish-white in color. The exterior surface displays a distinctive basaltic texture of light-colored, lath-shaped minerals with dark colored, interstitial mafic silicates and oxides. Some pits contain terrestrial material.

Petrography: Description and classification (A. Love, App): Sample has a subophitic texture of 600-800 μm exsolved Ca-rich and Ca-poor pyroxenes surrounded by ~1000 μm plagioclase laths. The sample is transected by shock veins and fault-bounded zones that show brecciated and recrystallization textures. Accessory minerals are: Si-Polymorph, Zircon, troilite, chromite, ilmenite.

Geochemistry: (A. Love, App): Low-Ca Pyroxene: Fs_64.4±0.8 Wo_2.3±0.7, Fe/Mn=42, n=12; Ca-Pyroxene: Fs_28.7±1.1Wo_43.1±1.4, Fe/Mn=41, n=9,); Calcic plagioclase: An_89.2±0.5Or_0.4±0.1, n=5).

Classification: HED (Eucrite, monomict)

Specimens: PARI holds the main masses (875.4 g and 136.9g ). A slice and an end cut weighing 20.82 g and one polished thin section are on deposit at App.