Dunite. Ain Ben Tili 004. Ungrouped Achondrite - 1.72 g - (1)

Ain Ben Tili 004 25.46857 N, 10.13846 W

Tiris Zemmour, Mauritania

Find: 2022

Classification: Ungrouped achondrite

The meteorite was found in 2022 in northern Mauritania and was subsequently purchased by Mohamed Ali Loud from Alian Muftah at the 2024 Munich mineral fair.

Physical characteristics: Many light grayish fragments, some of which are partly covered with black fusion crust.

Petrography: Achondritic breccia composed of a wide variety of up to 7 mm-sized euhedral to subhedral mineral fragments in a fine-grained cataclastic matrix of related material. The 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±0.1, Wo45.2±0.2, FeO/MnO=14±2, n=7; low-Ca pyroxene hosting exsolution lamellae: Fs31.6±0.1, Wo3.1±0.1 (Fs31.5-31.8, Wo3.0-3.1), FeO/MnO=26-29, n=7; Ca-pyroxene exsolution lamellae: Fs14.4±0.3, Wo42.4±0.2 (Fs13.8-14.7, Wo42.2-42.6), FeO/MnO=21-24, n=7; feldspar: An63.8-65.0, Ab33.6-34.9, Or1.3-1.5, 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 a certificate of authenticity.
Thanks for your interest.