Sample No.: ALHA77224

Location: Allan Hills

Field No.: 78012506

Weight (gms): 786.9

Meteorite Type: H4 Chondrite

Physical Description:

Specimen is angular, extremely weathered and friable. When meteorite was removed from cold storage and placed in the processing cabinet, many pieces fell off the main mass. There are many surface fissures that appear to continue throughout the meteorite. The B surface (not photographed) shows patches of fusion crust (very thin) and remnants of regmaglypts. The reddish-brown iron-oxide staining that is the prevalent color has an iridescent-like sheen on the B surface. The remaining exterior surfaces have small patches of a brownish-black fusion crust. Ice was observed in surface cracks when the specimen was removed from cold storage. This is not a complete specimen. The T surface appears to be a fracture surface. Small inclusions were observed on the weathered exterior surface. The T.S. and T.L. chips were taken from chips generated from sample when removed from cold storage. Approximate size : 13 x 14 cm.

Petrographic Description: Brian Mason

Chondritic structure is well-developed, with individual chondrules 0.2 - 1.0 mm in diameter; chondrule types include granular and porphyritic olivine, barred olivine, and fine-grained pyroxene. Minor amounts of troilite and nickel-iron are present, the nickel-iron being extensively weathered to limonite, which pervades the section. Black veining is prominent, the black color being partly due to fine-grained troilite. Microprobe analyses show olivine (Fa19) and orthopyroxene (Fs17) of essentially uniform composition.