TKW 4.4 kg. 17.5 x 11 x 11 cm. Mesosiderite
Location Map of Antarctic Falls
AMN writes:
Macroscopic Description - Roberta Score
Deep regmaglypts are present on the weathered surface of EET 87500, a mesosiderite. Only a few small patches of fusion crust remain on the surface. Abundant pyroxene inclusions, up to 2.5 cm in their longest dimension, are visible on the exterior. This meteorite is moderately weathered. The interior consists of approximately two-thirds silicates, coarse-grained pyroxene and plagioclase, and one-third metal. The exterior of EET 87501 has regmaglypts and a thin fusion crust with flow marks. The interior is identical to EET 87500 except that it appears to be more weathered.
Thin Section Description (,2) - Brian Mason
These sections are so similar in all respects that the specimens are almost certainly paired. They show a granular aggregate of approximately 50% pyroxene, 30% nickel-iron, and 20% plagioclase, with accessory merrillite and an SiO2 polymorph, probably tridymite. The grain size is relatively coarse, with individual pyroxenes and plagioclases up to 2 mm across; many pyroxenes are partly or completely converted into a mosaic of small granules. Weathering is minimal. Pyroxene compositions vary somewhat around a mean of Wo6Fs30: Wo3-14, Fs30-31, En54-62. Plagioclase composition is An91-96. The meteorite is a mesosiderite.
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