Sample No.: ALHA77160

Location: Allan Hills

Field No.: 77123006

Weight (gms): 70.42

Meteorite Type: L3 Chondrite

Physical Description:

Approximately 80% of surface is dark brown and angular with a slight patina. The patina is probably a result of chemical weathering and wind ablation. The remainder of the stone is covered by a spotty, thin, black fusion crust. This is not a complete specimen. The maximum dimension is approximately 5.5 cm. From field photographs it is apparent that the B surface was in contact with the ice.

Petrographic Description: Brian Mason

Chondrules abundant, 0.2-2.5 mm diameter, in a minimal amount of dark fine-grained matrix; some chondrules are spherical, but many are elliptical to irregular in form. Chondrules are mainly composed of barred or porphyritic olivine, some with polysynthetically twinned clinopyroxene. Interstitial glass in chondrules is pale gray, transparent to turbid. Minor subequal amounts of troilite and nickel-iron are present, the nickel-iron extensively altered to red-brown limonitic material, which pervades the section along chondrule boundaries. Microprobe analyses show a wide range of olivine composition, Fa3-Fa46, and a similar range in pyroxene composition. This range in composition, together with the presence of glass and twinned clinopyroxene, indicates type 3, and the small amount of nickel-iron suggests L group.