Yucca 040        34°44.063’N, 114°13.370’W

Arizona, United States

Find: 30 Apr 2005

Classification: Ordinary chondrite (H6)

History: Found by Dennis Asher. A 37.7 g sample was donated to Cascadia on March 9, 2013.

Physical characteristics: Brownish weathering patina, with patches of weathered fusion crust present on exterior surfaces.

Petrography: Chondrules and matrix are well integrated but chondrules are clearly discernable. BSE imaging shows that silicates are equilibrated throughout. Most plagioclase grains are >50 μm across, but enough larger grains (>100 μm) are present to warrant a type 6 classification (borderline type 5). Thin section is notable for containing a large number of chromite-plagioclase objects. Numerous subparallel hydroxide veins cut across the section, with approximately 50-60% of metal and sulfide replaced by weathering product, indicative of weathering grade W2 (borderline W3). Most olivine grains show mild to moderate undulose extinction with irregular fractures suggesting a shock stage of S2.

Geochemistry: (M. Hutson and A. Ruzicka, Cascadia) Olivine (Fa_18.6±0.3, N=14), low-Ca pyroxene (Fs_16.5±0.3Wo_1.5±0.3En_82.1±0.4, N= 11).

Classification: H6 based on mineral chemistry and texture.

Specimens: Cascadia holds 29.0 g in multiple pieces, in addition to two polished thin sections and a mounted butt. Mr. Dennis Asher holds the main mass.