Sample No.: ALHA81006

Location: Allan Hills

Field No.: 1549

Weight (gms): 254.9

Meteorite Type: Polymict Eucrite

Physical Description: Roberta Score

Shiny black fusion crust covers all but one fracture surface, though the fracture surface has millimeter sized patches of fusion crust on it. ALHA81006 looks typical of the other Allan Hills polymict eucrites. Two notable large clasts are: a fine-grained black clast that is 7 x 11 mm in diameter and a yellow eucritic clast which is covered with fusion crust, that is 15 x 13 mm in diameter. The latter clast can easily be plucked from the surface. Dimensions: 11 x 4.5 x 3.5 cm.

Petrographic Description: Brian Mason

The section shows a breccia of angular fragments of pigeonite and plagioclase up to 2 across, and some lithic clasts up to 3 mm across, in a matrix of comminuted pyroxene and plagioclase. The lithic clasts consist of pyroxene and plagioclase and range in texture from fine-grained basaltic to coarse-grained gabbroic. A little limonitic staining is present in the lithic clasts. Microprobe analyses show pigeonite with a wide range of composition: Wo1-15, En 34-59, Fs35-60, with Al2O3 0.3-2.2%, Cr2O3 0.2-1.5%, TiO2 0.2-0.4%. Plagioclase ranges in composition from An84-94 with a mean of An89. The meteorite is a polymict eucrite, and resembles other polymict eucrites collected at the Allan Hills.