Sample No.: ALHA78104

Location: Allan Hills

Field No.: 241

Weight (gms): 672.4

Meteorite Type: L6 Chondrite

Physical Description:

The W surface of the meteorite is partially covered with black fusion crust, which is weathering away. The remainder of the specimen is rough on a centimeter scale, and is weathered and stained by iron-oxidation. A large clast, ~7 mm., is present on the N surface, and a smaller clast, ~3 mm., that appears metallic, is present on the T surface. A number of smaller clasts, which appear to be metallic, are scattered over the surface of the specimen. When the specimen was cleaved during processing, a light gray matrix with metal particles was exposed. An area ~l cm. x 3 cm. in the matrix is a darker gray. A weathering rind, ~5 mm. deep, occurs along some exterior margins.

Petrographic Description: Brian Mason

Chondrules are sparse and have diffuse margins which tend to merge with the granular matrix, which consists of olivine and pyroxene with minor subequal amounts of nickel-iron and troilite, some plagioclase, and accessory chromite. Minor limonitic staining is present around nickel-iron grains. Well-preserved fusion crust, 0.5 mm thick, is present along one edge. Microprobe analyses give the following compositions: olivine, Fa24; pyroxene, Fs20, plagioclase, An10 The meteorite is an L6 chondrite.

ALHA78104 is an L6 chondrite similar to ALHA78103 in all respects.