Ksar Ghilane 022，未分组的无球粒陨石。 它的起源一直是最近科学研究争议的焦点。 - 1.47 g

Ksar Ghilane 022 (KG 022) 32.559°N, 9.508°E

Tatawin, Tunisia

Purchased: 2023

Classification: Ungrouped achondrite

History: 在突尼斯于2023年发现。2023年2月和11月由 Libyan 走私商向 Adam Aaronson 购买。随后在2024年2月向 Tucson Gem and Mineral Show 的 Craig Zlimen 提供了材料的部分样品，随后由 Robert Ward、Brian Caress 和 Ben Hoefnagels 购买。

Physical characteristics: 一大块石块（25 kg）以及与之一起发现的许多较小的碎块。大多数石块缺乏熔壳，外表呈斑驳的深灰和浅灰粒状外皮。然而，若干碎块部分覆有黑色熔壳。石块内部看起来像均粒状的浅灰色和白色颗粒组成的均质颗粒块。

Petrography: (A. Irving, UWS, and P. Carpenter, WUSL) 标本主要由 (>90 体积%) 几乎端端端元的辉石（多为等方晶粒，平均粒径约1.5 mm），伴随少量透辉石以及针铁铌、二方铝铁矿、铬-三铁矿、铝镁铁氧相等微量相。透辉石以小不规则包裹体或辉石晶粒内的稀疏细层形式出现，不同的辉石颗粒的宏观颜色显然反映了硫化物包裹体浓度的差异。石中存在若干二次方解石脉。

Geochemistry: Augite (Fs0.0-0.1Wo39.4-42.3, N = 3), enstatite (Fs0.1±0.0Wo0.9-3.6, N = 3). 氧同位素(K. Ziegler, UNM): 通过激光气化法对酸洗亚样本的分析结果分别为 δ17O 3.018, 2.926；δ18O 5.781, 5.559；Δ17O -0.034, -0.009 (所有数据线性化，TFL 斜率 = 0.528)。

Classification: Achondrite (ungrouped, Mg-rich clinopyroxenite). This meteorite is texturally and mineralogically very similar to ungrouped augite-rich achondrite NWA 15915. but does not exhibit the same degree of irrational exsolution of enstatite from the dominant constituent augite. Terrestrial pairing is further excluded by the different physical appearance of these two meteorites, different degree of weathering, and the fact that their purported find sites are hundreds of kilometers apart. Both of these meteorites may have some affinities to aubrites, but differ in being composed predominantly of almost Fe-free augite rather than enstatite.

Specimens: 41.3 g including one polished thin section at UWB; 677 g with Mr. R. Ward; 770 g with Mr. B. Caress; 674 g with Mr. B. Hoefnagels; 800 g with Mr. D. Dickens; remainder including the 25 kg main mass with Aaronson.

Shock stage: low
Weathering grade: low
Classifier: A. Irving, UWS, and P. Carpenter, WUSL

This lot has no reserve price and comes with its certificate of authenticity.
Thanks for your interest.