Sample No.: ALHA77231

Location: Allan Hills

Field No.: Y78010508

Weight (gms): 9270.0

Meteorite Type: L6 Chondrite

Physical Description:

This is a complete specimen, approximately 25.0 x 17.0 x 13.5 cm. All surfaces of the sample are covered with dull black fusion crust. The fusion crust has many polygonal fractures and is approximately 0.5 mm thick. There are several large fractures that cross the surface of the meteorite. There was snow/ice in the fractures when it was removed from cold storage. There are small areas along the fractures where the fusion crust has been removed and reveals greenish-gray material that does not have any obvious inclusions. When the meteorite was sawed a few light color clasts, as much as 1.5 cm in diameter, were observed. The metal in the meteorite has oxidation halos, although the weathering is not extensive.

Petrographic Description: Brian Mason

The thin section shows a granular aggregate of olivine and orthopyroxene, with minor subequal amounts of nickel-iron and troilite, and untwinned plagioclase. Chondrules are present, but their outlines are blurred and merge with the granular material. A little limonite is associated with some of the metal grains. Microprobe analyses show olivine (Fa24), orthopyroxene (Fs21), and plagioclase (An11) of uniform composition. The meteorite is classified as an L6 chondrite.