Frontier Mountain 01088

Antarctica

Found 2001 December 16

Achondrite (ureilite)

A crusted stone of 11.1 g was recovered. Mineralogy and classification (R. Carampin and A. M. Fioretti, UPad): FRO 01088 shows poikilitic texture and consists of olivine Fo75, pigeonite En76Wo10, and interstitial carbonaceous materials with oriented graphite lamellae. The pigeonite includes rounded crystals of olivine and flakes of graphite. Abundant, small diamond grains occur in the carbonaceous material, as revealed by its cathodoluminescence (strong blue-red dispersion) under the beam of the electron microprobe. Most olivine shows a very strong mosaicism, and locally hints of incipient solid-state recrystallization, corresponding to a shock stage S5/6. Secondary reduction has affected most silicate crystals. Weathering is minor, with thin limonite veins in fractures. Main mass, type specimen, thin section, MNA-SI.