Yucca 038        34°42.845’N, 114°10.697’W

Arizona, United States

Find: 2006 Oct

Classification: Ordinary chondrite (H5)

History: Purchased by Dennis Asher from the finder, John Wolfe, and later donated to Cascadia.

Physical characteristics: A dark reddish-brown weathering patina covers all exterior surfaces. Weathered fusion crust covers two sides.

Petrography: Chondrules (mean diameter = 0.67±0.29 mm, N=17) and matrix are well integrated. Chondrule mesostases are crystalline with plagioclase feldspar grains commonly ~5 μm across; larger interchondrule feldspars are 20-40 μm across. The sample contains about 0.3% metal, 1.8% troilite, and 5.3% hydroxide (weathering product, often in veins) based on modes determined from reflected light images Most olivine grains show mild to moderate undulose extinction with irregular or planar fractures, consistent with shock stage S2.

Geochemistry: (M. Hutson and A. Ruzicka, Cascadia) Olivine (Fa_19.3±1.6, N=52), low-Ca pyroxene (Fs_17.0±1.1Wo_1.3±0.8En_81.6±1.1, N= 19). Variability could be caused in part by unavoidable analysis overlap with weathering products.

Classification: H5 chondrite based on mineral chemistry and texture, although chondrule size, magnetic susceptibility, and potential pre-weathering metal content are more consistent with an L chondrite. A high proportion of hydroxide suggests weathering grade W3.

Specimens: Cascadia holds 9.7 g in multiple pieces, in addition to one polished thin section.