Northwest Africa 14709 (NWA 14709)

Morocco

Purchased: 2005

Classification: Ordinary chondrite (L5)

History: Sample was purchased at the Denver mineral show in 2005 from A. Aaronson, who acquired it from Morocco. Sample is catalogued at ROM as M59826.

Physical characteristics: Fist-sized individual nearly completely covered in fusion crust, with dun-brown weathering on most surfaces, suggesting that stone was 90% buried at find location. Moderate desert polished developed on exposed fusion crust surface. Physical properties: Magnetic susceptibilty of the 32.68 g type specimen is log χ (× 10^-9 m³/kg) = 4.16.

Petrography: Cut faces totalling 20 cm2 show a mottled, orange-weathered interior with sub-mm metal grains and aggregated metal clusters distributed along planes spaced at 1 to 3 cm. No chondrules are discernable. In polished thin section, silicates are pervasively Fe-stained. Chondrules are poorly delineated in a recraystallized matrix. Olivine and pyroxene show undulating to mosaic extinction and pervasive planar fracturing. In reflected light, metal and sulfide grains are subrounded and typically show embayment textures on surrounding chondritic silicates. Metal and sulfide is variably to strongly altered by Fe-oxides, which form haloes an in some cases completely replace metal and sulfide grains, with associated local vein networks of Fe oxides extending into surrounding silicates.

Classification: Ordinary chondrite: L5 (S4) W3. Low magnetic susceptibility for L chondrite reflects extensive weathering replacement of Fe metal with Fe oxides.

Specimens: Type specimen ROM; main mass DGregory