Northwest Africa 14619 (NWA 14619)

Morocco

Purchased: 2008

Classification: Ordinary chondrite (L6)

History: Sample was purchased at the Tucson mineral show in 2008 from A. Aaronson, who acquired it from Morocco. Sample is catalogued at the Royal Ontario Museum as M58919.

Physical characteristics: Small, dark, fractured individual showing fusion crust on two thirds of surfaces. All surfaces including broken face have moderate desert polish.

Petrography: Cut faces show dark brown interior with minor presence of disseminated sub-mm metal grains and a network of grey fracture-fill veins. In thin section, the rock is very dark, showing an extensive Fe-oxide vein network. Chondrules are very poorly defined. No large grains are present and the dominant texture is one of fragmentation. Olivine exhibits undulatory to mosaic extinction, along with some internal planar fracturing. Silicates show strong Fe-staining. In reflected light, sulfide grains are abundant and some FeNi metal grains show alteration rims with Fe-oxides, that are associated with the Fe-oxide vein network.

Classification: Ordinary chondrite L6 (S3) W2. Lack of chondrule definition suggests type 6. Low metal content and prevalence of sulfides suggests L classification. Moderate shock S3 is indicated by olivine shock damage. Pervasive Fe-oxide veining and breakdown of metal and sulfides suggests weathering W2. Magnetic susceptibility of log χ (× 10^-9 m³/kg) = 4.50 is consistent with L chondrite.

Specimens: Type specimen ROM; main mass DGregory