Northwest Africa 13044 (NWA 13044)

(Northwest Africa)

Purchased: 2019

Classification: Ordinary chondrite (H3)

History: (Ziyao Wang) Purchased by Ziyao Wang from Fayssal Mezgouri at the mineral show in Beijing in Nov. 2019

Physical characteristics: (Ziyao Wang) A gray-black stone of 326 g with fusion crust.

Petrography: (R. Bartoschewitz, Bart) various types of well developed chondrules, dominantly 0.3-1.5 mm (but some up to 5 mm, av. 0.47 mm, n=200) with abundant dark rims of troilite and oxidized metal, chrondrule and mineral fragments set in a black matrix, together with troilite and mostly oxidized metal (unaltered metal about 5 vol%).

Geochemistry: (R. Bartoschewitz, Bart, P. Appel and B. Mader, Kiel) Olivine Fa_16.4 (0.4-21.3; Fe/Mn=5-355, av. 73; n=33); poor Ca-pyroxene Fs_9.3 (2.3-15.5) Wo_1.3 (0.2-1.9; n=4); augite En₄₉Fs₁₁Wo₄₀ (n=1). Kamacite Ni=4.1, Co=1.1 (n=3); taenite Ni=41.1-48.7, Co=0.8-1.1 (n=2); tetrataenite Ni=53.4, Co=1.7 (n=1); wt%. O-isotopes (A. Pack, T. Di Rocco, and A. Gehler, UGött): δ¹⁷O(‰) = 3.044, δ¹⁸O(‰) = 4.109, D’17O(0.528) (ppm) = 0.875. Magnetic susceptibility (R. Bartoschewitz, Bart) log χ (× 10^-9 m³/kg) = 3.91-3.95

Classification: Ordinary chondrite (H3, S2, W3). For an H chondrite (confirmed by O-isotopes), it has unusually low metal content, magnetic susceptibility, and high Co in kamazite.

Specimens: 21.6 g on deposit at IfP, Ziyao Wang holds the main mass, and 31 g with Bart. Polished thin sections with Bart + IfP