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Catalog Data

Expedition:
Antarctic Search for Meteorites (ANSMET)  Search this
Place:
Antarctica
Collection Date:
1999
Notes:
# NASA data for EET 99408 Weathering: A/B Fracturing: A/B Pairing: EET 87509 Fs: 21-27 mol %
Both of these achondrites have black shiny fusion crust with polygonal fractures covering 20% of the exterior. The interior is concrete gray with angular to sub angular black, white, tan and gray clasts. Olivine crystals are visible. There is no visible metal, but thin minor fractures are present.
These meteorites are so similar that a single description suffices. The sections show a groundmass of comminuted pyroxene and plagioclase (up to 0.5 mm) with fine- to coarse-grained basaltic and pyroxenitic clasts ranging up to 1 mm. Pyroxene consists of orthopyroxene (Fs₁₇₋₂₇Wo₀₋₁), pigeonite (Fs₄₂₋₅₀Wo₁₃₋₁₅) and augite (Fs₂₄Wo₃₇). The Fe/Mn ratio of pyroxene is ~30. Plagioclase is An₈₀₋₉₄Or₀₋₁. The meteorites are howardites.
Record Last Modified:
21 Sep 2023
Specimen Count:
1
Other Numbers:
Pairing Group : 99400
See more items in:
Mineral Sciences
Meteorites
Antarctic Polished Thin Section Collection
Digital Collection: Micrographs
Data Source:
NMNH - Mineral Sciences Dept.
GUID:
http://n2t.net/ark:/65665/3c30efd17-bb86-41b1-9868-ae361e828468
EDAN-URL:
edanmdm:nmnhmineralsciences_1039691