Howardite
TKW 40.5 grams. 30 x 30 x 25 mm.
Fall not observed. Found 1987 in Antarctica.
Location Map of Antarctic Finds
AMN writes:
Macroscopic Description - René Martinez
This brecciated achondrite retains black fusion crust on about 50% of its exterior. Fractured surfaces appear fresh. Inclusions are mostly small mineral fragments of either pyroxene or plagioclase, but there are two conspicuous clasts: one about 1 cm x 0.5 cm and the other about 0.5 x 0.5 cm in cross-section. One was sampled for thin sectioning. The interior matrix is light gray.
Thin Section Description - Brian Mason
EET87528,8 is a microbreccia of pyroxene (both orthopyroxene and pigeonite) and plagioclase clasts up to 2.2 mm in maximum dimension in a matrix of comminuted pyroxene and plagioclase. Orthopyroxene is more abundant than pigeonite, and occurs as larger clasts. EET87528,10 consists mainly of a large (9 x 7 mm) diogenite clast, bordered by material like 87528,8. Pyroxene compositions show the following range: Wo1-24, Fs21-60, En31-76; pyroxene in the diogenite clast is slightly variable, averaging Wo2Fs23. Plagioclase composition is An80-95. The meteorite is a howardite, but appears to differ from EET87503 and other howardites in that group.
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