Sample No.: ALHA77305

Location: Allan Hills

Field No.: B77123108

Weight (gms): 6444.0

Meteorite Type: L6 Chondrite

Physical Description:

Snow ice? was observed in cracks of the meteorite when it was removed from the freezer. The exterior surface does not have a fusion crust with the exception of an ~5 cm diameter area, which is dark and 1-2 mm thick, however, it does have a reddish-brown weathering rind. The iron-oxide staining that is apparent on the exterior surface is heavier adjacent to the several fissures which are present on the surface of the meteorite. It appears that the roundness of the stone may be due to exfoliation. Rounded inclusions are apparent on the surface. It appears that the entire specimen has experienced moderate weathering on the exterior surface. During chipping ~25% of the specimen fell off along a fissure. The interior portion is both weathered and fresh in appearance. Fresh metal is apparent on surfaces not adjacent to fissures. After sawing the specimen, small metal chips were visible throughout the sample. The sample is very hard, even though many parallel cracks run throughout the entire sample.

Petrographic Description: Brian Mason

Chondrules are sparse and poorly defined, merging with the granular groundmass. Troilite and nickel-iron are present in minor, approximately equal amounts. About 10% of plagioclase is present, as small untwinned grains. The meteorite is relatively unweathered, with a limited amount of limonitic staining associated with nickel-iron grains. Microprobe analyses show olivine (Fa24) and orthopyroxene (Fs21) of uniform composition.