Sample No.: ALHA78112

Location: Allan Hills

Field No.: 260

Weight (gms): 2485.0

Meteorite Type: L6 Chondrite

Physical Description:

Snow and/or ice was present on the sample, ~14 x 13 x 13 cm., when it was removed from cold storage. The specimen is covered with a 0.5 mm to 1 mm. fusion crust on four surfaces. On one of these surfaces the fusion crust has weathered to a brown color, while on the other surfaces the fusion crust is black. The S surface is a fracture surface that is 80% weathered and stained by iron-oxidation. The unweathered material is yellowish and appears homogeneous. Three fractures are present on the sample, two of these appear to be shallow. Sawing the specimen during processing revealed a light gray matrix material with oxidation halos around most of the visible metallic grains. Two interior cracks exist, but with no preferential weathering along them. Clasts as much as 3 mm. in diameter are present.

Petrographic Description: Brian Mason

Chondrules are sparse and ill-defined, their borders tending to merge with the granular groundmass, which consists mainly of olivine and pyroxene, with minor subequal amounts of nickel-iron and troilite, plagioclase, and accessory chromite. A moderate amount of limonitic staining is associated with the nickel-iron grains. Microprobe analyses give the following compositions: olivine, Fa25; pyroxene, Fs20; plagioclase, An10. The meteorite is an L6 chondrite. ALHA78114 is another L6 chondrite, similar to ALHA78112 in all respects.