Northwest Africa 14257 (NWA 14257)

Morocco

Purchased: 2013

Classification: HED achondrite (Eucrite)

History: A single stone found in Morocco by nomads. Purchased by Graham Ensor in Ensisheim, France, in 2013. Date of find unknown.

Physical characteristics: Physical Characteristics: 6 pieces - description is of largest stone (~3.5 cm). Dark, sandblasted with intact fusion crust remaining on exterior. Irregular white and grey clasts, no observable melt veins in hand specimen.

Petrography: The meteorite displays a relatively coarse-grained texture with larger, subrounded clast of pyroxene (up to ~ 2 mm) and plagioclase (up to ~ 3 mm). Pyroxene exsolution lamellae are observed with a wide range of thicknesses( from ~ 2.5-10 µm). Known accessory phases include: A silica phase and chromite.

Geochemistry: Mineral Composition and Geochemistry: (T. J. Barrett, T. S. Hayden, OU) Feldspar (An₉₀Ab₁₀, n = 17), orthopyroxene (Fs_54±1En_43±2Wo_3±1, FeO/MnO = 31±4, Mg# = 44±2, n = 41), pigeonite (Fs_50±3En_40±2Wo_10±4, FeO/MnO = 30±2, Mg# = 45±2, n = 30), augite (Fs_27±5En_34±2Wo_39±6, FeO/MnO = 30±3, Mg# = 56±4, n = 16).

Classification: Eucrite

Specimens: 25.8 g type specimen held at OU. Graham Ensor holds the main mass.