Northwest Africa 14842 (NWA 14842)

Morocco

Purchased: 2015

Classification: Ordinary chondrite (L5)

History: Sample was purchased in 2015 from A. Aaronson at the Tucson mineral show who acquired it from Morocco. Sample is catalogued at the ROM as M60273.

Physical characteristics: Rounded, blocky, fist-sized individual with concave surfaces, showing remnant dark fusion crust on nearly all surfaces. Broken and fusion crust surfaces have mature desert polish. Physical properties: Magnetic susceptibility measured for the 30.35 g type specimen is log χ (× 10^-9 m³/kg) = 4.18.

Petrography: Cut faces show disseminated metal in blebs up to mm size, with cm2 areas where metal appears absent due to weathering. Chondrules are present but difficult to delineate in an patchy brown- to orange-weathered matrix. In polished thin section, chondrules are difficult to delineate and matrix is recrystallized to moderate grain size. Silicates are pervasively stained to tan colors with weathering. Olivine and pyroxene grains typically show undulatory extinction. In reflected light, metal grains are sparse and typically surrounded by Fe oxide haloes. Sulfide grains are abundant (2 vol%) and typically anhedral, up to 200 µm size. Fe oxides commonly fill pockets that appear to have replaced metal and otherwise occur filling cracks.

Classification: Ordinary chondrite: L5 (S2) W3. Magnetic susceptibilityis consistent with weathered L chondrite.

Specimens: Type specimen location: ROM. Main mass: Gregory.