Antarctic Search for Meteorites (ANSMET) Search this
Place:
Antarctica
Collection Date:
1993
Notes:
# NASA data for QUE 93341 Weathering: B Fracturing: A Pairing: QUE 93336 Fa: 23 mol % Fs: 18 mol %
Both of these small specimens are identical. The small amount of fusion crust that remains is dull and dark brown. The rest of the exterior surfaces have a polished, waxy appearance. The brownish-gray interior shows abundant crystal faces.
The sections are so similar that the meteorites are certainly paired. They show anhedral grains of olivine and pyroxene in a black matrix. Considerable weathering is indicated by brown limonite rimming many grains. In reflected light the margins of the silicate grains are seen to contain numerous minute metal grains, probably the product of reduction from their iron content by the carbonaceous matrix. During polishing the probable presence of microscopic diamonds in the matrix was noted. Microprobe analyses show that most of the olivine and pyroxene has uniform composition; olivine, Fa₂₃; pyroxene Wo₁₀Fs₁₈; but the margins of the grains show greatly reduced iron contents. The meteorite is a ureilite, and appears to be relatively unshocked.
