Northwest Africa 11517 (NWA 11517)

Northwest Africa

Purchased: 2017

Classification: Lunar meteorite (feldspathic breccia)

History: Four individuals weighing a total of 88 g were found near Tindouf, Algeria. John Sinclair purchased the stones from a Moroccan meteorite hunter at the Sainte Marie Aux Mines mineral show in France during June of 2017.

Physical characteristics: Sample is irregular-ovoid shaped and lacks fusion crust. The exterior surface is weathered and light orangish-gray in color. The stone shows brecciated texture composed of dominant light-colored clasts in a dark grey matrix. FeNi grains are present in several slices. Pits from weathering of clasts and vesicles contain orange caliche.

Petrography: Description and classification (A. Love, App) Sample is a polymict breccia composed of 0.5-3 mm irregularly shaped lithic and mineral clasts set within a micro-vesiclar, melt matrix. Clasts are composed of poikilitic gabbro, vitrophyric, anorthosite, crystalline impact melt, and basaltic lithologies. Minerals clasts include olivine, exsolved Ca-rich and Ca-poor pyroxene, baddeleyite, ulvospinel, ilmenite, chromite, FeS, kamacite, taenite, Si-polymorph.

Geochemistry: (A. Love, App) Olivine (Fa_18.65-53.01, FeO/MnO=83.29-109.49, N=12), Opx (Fs_16.43-42.54 Wo_2.92-4.47, FeO/MnO=53.16-60.73, N=5), pigeonite (Fs_40.64-67.00 Wo_5.14-11.16, FeO/MnO=54.93-67.00, N=8); augite (Fs_17.44-36.61 Wo_19.71-43.48, N=8); pyroxeferroite Fs_70.28 Wo_5.8, FeO/MnO=60.5, N=1); plagioclase An_95.55-98.72 Or_0.00-0.27, N=15).

Classification: Lunar (feldspathic breccia). Textures and mineral compositions indicate this sample is a feldspathic breccia. FeO/MnO ratios from olivine and pyroxene and An-content of plagioclase suggest this sample is a lunar feldspathic breccia.

Specimens: J. Sinclair holds the main masses. An individual and a slice weighing 17.6 g and one polished thin section are on deposit at App.