Description: On offer is a slice displaying large Olivine mineral clasts. The slice is of a rare and mysterious meteorite; NWA 13955 which is officially classified as an Achondrite-Ungrouped (Ultramfic, Vesicular). It is mainly composed of Olivine, Pyroxene and Plagioclase and small amounts of Chromite. It also contains a lots of vesicles. This meteorite was featured in an abstract in the 84th Annual Meeting of The Meteoritical Society 2021 ("OLIVINE-BEARING IGNEOUS ROCKS UNLIKE EUCRITES OR DIOGENITES DERIVED FROM UNKNOWN DIFFERENTIATED PARENT BODIES") by Dr. A. J. Irving and his colleagues. Weight: 4.0 grams This specimen comes with a signed COA and a protection box We offer combined shipping We are a Global Meteorites Association trusted member #G0064 Official entry in the Meteorites database bulletin : Northwest Africa 13955Basic informationName: Northwest Africa 13955 This is an OFFICIAL meteorite name. Abbreviation: NWA 13955 Observed fall: No Year found: 2020 Country: Algeria Mass: 1760 g Classification history:Recommended: Achondrite-ung [explanation] This is 1 of 118 approved meteorites classified as Achondrite-ung. [show all] Search for other: Achondrites, Ungrouped achondrites Comments:Approved 8 Jun 2021WriteupWriteup from MB 110: Northwest Africa 13955 (NWA 13955) Algeria Find: 2020 Classification: Ungrouped achondrite History: A single 1760 g stone was recovered by a group of Saharawi meteorite hunters in the Algerian part of the Erg Chech region during the summer of 2020, and then purchased by Ali Salamu from a dealer in Nouadhibou, Mauritania. Physical characteristics: The interior of the specimen has an overall light brown color with small orange patches, and contains sporadic smooth-walled vesicles. Petrography: (A. Irving, UWS and P. Carpenter, WUSL) Cumulate texture. Composed of subhedral grains of olivine (~20 vol.%) and low-Ca pyroxene (~70 vol.%, zoned from small orthopyroxene cores to thick mantles of pigeonite) together with intercumulus calcic plagioclase (<10 vol.%) and accessory chromite (low-Ti to Ti-free), metal with (Fe/Ni ratios intermediate between those for typical typical kamacite and taenite), and Fe oxide (possibly representing altered sulfide). Sporadic vesicles or vugs are present. Geochemistry: Olivine (Fa33.8-34.8, FeO/MnO = 41-44, N = 4), orthopyroxene cores (Fs19.1-20.5Wo0.7-0.8, FeO/MnO = 29-30, N = 2), low-Ca pyroxene (Fs26.8-27.6Wo3.4-5.2, FeO/MnO = 26-28, N = 3), pigeonite (Fs25.1-26.7Wo7.7-7.8, FeO/MnO = 28-29, N = 2), plagioclase (An79.9-86.3Or1.1-0.5, N = 3). Oxygen isotopes (K. Ziegler, UNM): analyses of acid-washed subsamples by laser fluorination gave, respectively, δ17O 1.716, 1.777, 1.725; δ18O 3.828, 3.873, 3.782; Δ17O -0.305, -0.268, -0.272 (all data linearized). Classification: Ungrouped achondrite (ultramafic, vesicular). The meteorite is different from diogenites with orthopyroxene present as cores only, and predominance of pigeonite. The oxygen isotopic composition plots below the values for diogenites and typical eucrites. Specimens: 20.7 g including one polished thin section at UWB; remainder with Mr. A. Salamu.
Price: 200 USD
Location: Bagarmossen
End Time: 2024-10-29T15:04:09.000Z
Shipping Cost: 15 USD
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Restocking Fee: No
Return shipping will be paid by: Seller
All returns accepted: Returns Accepted
Item must be returned within: 30 Days
Refund will be given as: Money Back
