Northwest Africa 12914 (NWA 12914)

(Northwest Africa)

Purchased: 22 Jan 2017

Classification: Ordinary chondrite (L6)

History: BBaecker purchased an NWA meteorite on Ebay on January 22, 2017, and donated pieces to Cascadia two weeks later.

Physical characteristics: Cascadia received two somewhat crumbly pieces lacking fusion crust. Samples are light gray with metal/sulfide bumps protruding from the silicates, with rust patches near opaques. One end of one piece is heavily weathered, and represents the stone’s exterior.

Petrography: (M. Hutson, A. Ruzicka, R. Kostynick, Cascadia): The texture of the silicates in thin section is well-integrated; indistinct chondrules are barely visible. Plagioclase feldspar grains up to 120 microns across are present. Almost all of the metal in the section is concentrated in one long roughly ovoid patch (~1.3 × 0.7 mm). Abundant sulfide grains in section are all smaller (<= 0.6 mm) than the metal grain.

Geochemistry: Mineral compositions and geochemistry: Olivine and pyroxene grains are equilibrated: Fa_25.2±0.6, N=11; Fs_21.0±0.1Wo_1.5±0.3, N=12.

Classification: Ordinary chondrite (L6) based on chemistry and texture.

Specimens: Cascadia holds 12.2 g in multiple fragments, in addition to a polished thin section. The main mass is held by BBaecker: Bastien Baecker, Huntsville, AL.