Northwest Africa 10952 (NWA 10952)

(Northwest Africa)

Purchased: 2005

Classification: Enstatite chondrite (EL4)

History: Purchased by an anonymous collector from a dealer at the Munich Show in 2005 and subsequently acquired by the Hollis Collection.

Physical characteristics: (P. Sipiera, PSF) A "6 sided" individual stone (17208 g) with a rounded triangular or pyramid shape, and approximate dimensions of 29 × 24 × 28 cm. Exterior surfaces range from brown-colored, smooth fusion crusted areas to rough eroded regions to a rusty-orange colored area. A cut surface reveals a dark brown interior with numerous altered metal grains and obvious round chondrules.

Petrography: (A. Irving and S. Kuehner, UWS) Well-formed RP chondrules (apparent diameter 500-1800 μm, mean 800 μm) are set in a relatively coarse-grained matrix containing prismatic enstatite grains and altered metal. Apart from predominant enstatite, accessory minerals include diopside, kamacite, daubreelite, troilite, schreibersite and oldhamite (partly altered to gypsum).

Geochemistry: Enstatite (Fs_0.4-1.2Wo_0.5-0.6, N = 3), diopside (Fs_0.2Wo_47.8), metal (in wt.%, Si 0.20-0.21, Ni 5.5-5.9, Co 0.43-0.50, N = 4). Magnetic susceptibility log χ (× 10^-9 m³/kg) = 4.87.

Classification: Enstatite chondrite (EL4).

Specimens: 177 g including one polished thin section at PSF; remainder in the Hollis Collection.