Northwest Africa 14054 (NWA 14054)

Morocco

Purchased: 2020 Jan

Classification: Enstatite chondrite (EL6)

History: Purchased from a Moroccan dealer at the Tucson show

Physical characteristics: (R. Szczuczko) The exterior of the small flat brown stone is weathered with numerous fractures. The interior reveals a lightly mottled brown surface with numerous filled fractures and local patches of metal flecks.

Petrography: (C. Herd and A. Locock, UAb) Optical examination of a thin section shows an equilibrated and highly fractured texture, with numerous crosscutting iron oxide veins and veinlets. EMP- and SEM-based backscattered imaging of a polished mount shows that accessory minerals include troilite, daubreelite, kamacite and schreibersite; these are surrounded by iron oxide. No Mn,Mg sulfides were found. Two possible relict chondrules were identified.

Geochemistry: (C. Herd and A. Locock, UAb) Data obtained by EMP examination of carbon-coated probe mount: Enstatite Fs_0.7±0.4Wo_1.4±0.0 (n=40); Plagioclase An₁₆Ab₈₀Or₄ (n=2). Kamacite (wt%) Fe 91.7±0.8, Ni 6.0±0.1 , Co 0.26±0.2 , Si 1.69±0.06 (n=13). Troilite (wt%) Cr 0.85±0.25 (maximum 1.67), Ti = 0.54±0.03.

Classification: Enstatite chondrite, EL6, based on mineralogy, equilibrated texture, and Si content in kamacite. Belongs to the ELa subgroup of Weyrauch et al. (2017) based on Cr and Ti contents of troilite.

Specimens: Type specimen of 25.2 g is at UAb. Main mass, polished mount and thin section with the owner.