Dunite. Ain Ben Tili 004. Ungrouped Achondrite, - 1.79 g - (1)

Ain Ben Tili 004 25.46857 N, 10.13846 W Tiris Zemmour, Mauritania Find: 2022 Classification: Ungrouped achondrite History: The meteorite was found 2022 in northern Mauritania and subsequently purchased by Mohamed Ali Loud from Alian Muftah at the 2024 Munich mineral fair. Physical characteristics: Many light grayish fragments some of which partly covered with black fusion crust. Petrography: Achondritic breccia composed of a great variety of up to 7 mm sized euhedral to subhedral mineral fragments in a fine-grained cataclastic matrix of related material. Most abundant are compositionally homogeneous olivine (about 85 vol%), exsolved pyroxene (about 8 vol%) and feldspar (about 2 vol%) grains. Zoned olivines are rare. Accessories (about 5 vol%) include silica, chromite, FeS, kamacite, and taenite. Contains augite-chromite symplectites. Geochemistry: compositions of individual olivine grains: Fa14.4±0.1, FeO/MnO=39±2, n=7; Fa17.2±0.1, FeO/MnO=39±2, n=7; Fa20.4±0.1, FeO/MnO=40±2, n=7, Fa36.0±0.2, FeO/MnO=46±3, n=7; zoned olivine: Fa10.8±1.0 (Fa10.1-12.7, FeO/MnO=39±3, n=7); Ca-pyroxene in symplectites: Fs5.4±0.1Wo45.2±0.2, FeO/MnO=14±2, n=7); low-Ca pyroxene host to exsolution lamellae: Fs31.6±0.1Wo3.1±0.1 (Fs31.5-31.8Wo3.0-3.1, FeO/MnO=26-29, n=7); Ca-pyroxene exsolution lamellae: Fs14.4±0.3Wo42.4±0.2 (Fs13.8-14.7Wo42.2-42.6, FeO/MnO=21-24, n=7); feldspar: An63.8-65.0Ab33.6-34.9Or1.3-1.5, n=7; chromite: Mg#31.4±2.8, Cr#75.1±1.9, n=10 Classification: Ungrouped achondrite, dunitic breccia. Likely paired with NWA 15717 and related meteorites. Shock stage: low Weathering grade: low Classifier: A. Greshake, MNB. This lot comes with certificate of authenticity. Thanks for your interest.

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