Sample No.: ALH83108

Location: Allan Hills

Weight (g): 1519.4

Field No.: 2120

Dimensions (cm): 16 x 8 x 6

Meteorite Type: C3O Chondrite

Macroscopic Description: Carol Schwarz

Approximately 80% of this carbonaceous chondrite is covered with dull, polygonally fractured fusion crust. The exterior matrix exposed on areas devoid of fusion crust has weathered to a greenish-gray color. The interior is medium gray, contains minute metal flecks, and shows no appreciable weathering.

Thin Section (,4) Description: Brian Mason

The section shows numerous chondrules, chondrule fragments, and irregular mineral aggregates in a turbid brown matrix which contains minor subequal amounts of nickel-iron and sulfide. The chondrules are small and fairly uniform in size, 0.2-0.6 mm across. Most of the chondrules consist of granular or porphyritic olivine; pyroxene is rare. Microprobe analyses show olivine compositions ranging from Fa0.9 to Fa38, with a marked peak at the high-iron end; pyroxene compositions range from almost pure MgSiO3 to Wo5Fs16, with a mean of Wo2Fs6. The meteorite is a C3O chondrite. It resembles the other C3O chondrites from the Allan Hills (77003, 77029, 82101), and the possibility of pairing should be considered.