Sample No.: ALHA77001

Location: Allan Hills

Field No.: 78010210A

Weight (gms): 252.0

Meteorite Type: L6 Chondrite

Physical Description:

Fusion crust is mainly missing. One large surface was produced by breaking after fall; complementary fragment is probably in the collection. Original surfaces are considerably weathered. Sawed surface showed unweathered metal particles to within ~1 cm of the surface. Specimen contains several cracks and appears slightly friable. One existing broken surface contained an irregular, medium gray, fine grained clast ~0.7 cm across. No clasts were noted on the sawed face.

Petrographic Description: Brian Mason

Antarctic meteorite ALHA77001 is a typical L6 chondrite. Chondrules are sparse and poorly defined; maximum diameter is 1.9 mm. Major minerals are olivine (Fa₂₅) and orthopyroxene (Wo_1.7En₇₇Fs₂₁). About 10% of plagioclase (Ab₈₃An₁₁Or₆) is present as untwinned birefringent grains up to 0.15 mm across. Minor phases are nickel-iron (≈8%), troilite (~6%), diopside (~4%), chromite (<1%) and merrillite (<1%). The small section examined shows no signs of shock or veining. A moderate amount of limonitic staining is present around most nickel-iron grains, none around troilite.