Sample No.: ALH85121

Location: Allan Hills

Weight (g): 55.3

Field No.: 2629

Dimensions (cm): 5 x 4 x 1

Meteorite Type: H3 Chondrite

Macroscopic Description: Roberta Score

Frothy brown and black fusion crust covers the T-surface of this mushroom-shaped stone while thick (2 mm) black ropy fusion crust covers the B surface. Numerous fractures penetrate the interior which is moderately to heavily weathered. A weathering rind that ranges in thickness from <1 mm to 5 mm is present. The matrix is medium gray in color with numerous clasts/chondrules visible.

Thin Section (,3) Description: Brian Mason

The section shows abundant chondrules and chondrule fragments, up to 3 mm across, in a matrix of fine-grained olivine and pyroxene with moderate amounts of nickel-iron and troilite (sometimes rimming chondrules). Chondrule types include granular and porphyritic olivine and olivine-pyroxene, and radiating or cryptocrystalline pyroxene. Weathering is extensive, with limonitic staining and small areas of red-brown limonite throughout the section. Microprobe analyses show olivine and pyroxene with a considerable range in composition: olivine, Fa9-20 (CV FeO is 16); pyroxene, Fs3-31. The content of nickel-iron suggests H group, and the variability of olivine and pyroxene compositions type 3, hence the meteorite is tentatively classified H3 (estimated H3.8).