Sample No.: ALHA78042

Location: Allan Hills

Field No.: 268

Weight (gms): 214.1

Meteorite Type: L6 Chondrite

Physical Description:

The T surface of this ~5.5 x 4.5 x 5.0 cm sample has a 4 x 3 cm area where reddish black fusion crust has been preserved. The remainder of the sample is composed of fracture surfaces that are weathered reddish-brown. Sawing of the sample revealed a light gray matrix with both rounded and irregular inclusions, as much as 1 mm in diameter. The exterior margins of the sample are weathered and stained by iron-oxidation, while the interior of the sample appears relatively fresh.

Petrographic Description: Brian Mason

Chondritic structure is poorly developed; the chondrules are sparse and poorly defined and tend to merge with the granular groundmass, which consists largely of olivine and pyroxene, with minor plagioclase, nickel-iron, and troilite, and accessory chromite. Some of the nickel-iron grains are unusually large, ranging up to 2.5 mm. A minor amount of brown limonitic staining is present around the nickel-iron grains. Microprobe analyses give the following compositions: olivine, Fa24; orthopyroxene, Fs20; plagioclase, An10, The meteorite is classified as an L6 chondrite.