Northwest Africa 14988 (NWA 14988)

(Northwest Africa)

Purchased: 2019

Classification: Primitive achondrite (Winonaite)

History: Purchased by Ziyao Wang in April 2019 from Saeed Haddany in Erfoud, Morocco.

Physical characteristics: Single stone. Orange-brown weathered exterior. Saw cut reveals a fine-grained texture of silicates and oxidized iron patches.

Petrography: (A. Ross and C. Agee, UNM) Microprobe and reflected light microscope examination of a polished mount shows a texturally equilibrated mosaic of enstatite and diopside with grain size in the range 100-300 μm, many triple junctions are present. Nearly all of the primary metal has been oxidized. No feldspar was observed in the microprobe mount.

Geochemistry: (A. Ross, UNM) Olivine Fa_2.4±0.5, Fe/M=10±2, n=6; enstatite Fs_3.1±0.0Wo_1.1±0.1, Fe/Mn=8±0, n=3; diopside Fs_1.2±0.0Wo_47.3±0.3, Fe/Mn=6±1, n=3; plagioclase Ab_81.7±1.4An_14.8±2.0, n=4. Oxygen isotopes (K. Ziegler, UNM): 3 acid-washed fragments analyzed by laser fluorination gave δ¹⁸O= 4.959; 5.390; 4.856; δ¹⁷O= 2.044, 2.291, 2.021; Δ¹⁷O= -0.574, -0.555, -0.543 (linearized, all per mil, TFL slope=0.528).

Classification: Primitive achondrite (Winonaite) based on oxygen isotopes which plot in the winonaite field; also based on the very magnesian olivines and pyroxenes with low Fe/Mn values.

Specimens: 21.4 g including a probe mount on deposit at UNM, WangZ holds the main mass.