Yucca 031        34°45’28.67"N, 114°15’29.38"W

Arizona, United States

Find: 2013 Dec 14

Classification: Ordinary chondrite (H6)

History: A 34.3 g meteorite was found by Twink Monrad while she was hunting for Franconia meteorites with a metal detector. It was found at the top of a hill buried 18 cm deep in soft dirt. The stone appears to be oriented, as it is cone shaped with a slight rollover lip on the back side.

Physical characteristics: Exterior of the stone is covered with brownish weathered fusion crust. The interior is brown with light-colored patches. It has an even distribution of fine metal and troilite grains, estimated 45 areal %. A few chondrules to 1 mm are visible.

Petrography: The stone is largely recrystallized with sparse chondrules. A probe section shows several BO chondrules. Plagioclase grains up to 100 μm are abundant. Chromite is irregularly shaped, to 500 μm. Metal is dominated by irregularly shaped single-crystal kamacite grains to 0.7 mm, which lack shock features. Tetrataenite and plessite are rare. Troilite grains are single crystals and lack shock features. Kamacite/taenite grain boundaries are smooth. One 20 μm native Cu nugget was found. Weathering is minor.

Geochemistry: (L. Garvie, ASU) Olivine Fa_19.7±0.5, FeO/MnO=38.7±2.0, n=9; low Ca pyroxene Fs_17.3±0.2Wo_1.2±0.2, FeO/MnO=23.5±0.8, Cr₂O₃ = 0.11±0.05 wt%, n=12; high Ca pyroxene Fs_6.2±0.5Wo_45.5±1.6, FeO/MnO=18.5±1.0, Cr₂O₃ = 0.7±0.1 wt%, n=5; kamacite Ni=6.1?0.4 wt% and Co=0.5±0.0 wt%, n=6.

Classification: Ordinary chondrite, H6, S1, W1

Specimens: 12.1 g at ASU.