Northwest Africa 14692 (NWA 14692)

Algeria

Purchased: 2021

Classification: HED achondrite (Eucrite)

History: Fabien Kuntz purchased a single 646.1 g stone from a meteorite dealer in Tindouf, Algeria, in Dec. 2021.

Physical characteristics: Sample is ~50% of sample is coated with a dark brown fusion crust. The brecciated nature of its interior is evident on the fusion crusted face and the trailing face. The cut face shows the interior is a light-colored breccia with occasional dark carbonaceous clasts.

Petrography: Description and classification (A. Love, App): Sample is a polymict breccia composed of a mixture of types of basaltic and cumulate textured eucrite lithic clasts and related mineral fragments. Sample also contains mm-sized carbonaceous chondrite clasts. Rare pyroxenes are crosscut by veins of fayalite. Additional minerals are: Ilmenite, troilite, a silica polymorph, phosphates, chromite, FeNi metal and secondary calcite.

Geochemistry: (A. Love, App) low Ca pyroxene (Fs_56.2±7.1Wo_2.7±1.0, Mg#29.3-52.3, Fe/Mn=30.3±1.6, n=16); pigeonite (Fs_58.2Wo_6.2, Fe/Mn=29.6, n=1); high Ca Pyroxene (Fs_27.8±6.7Wo_42.4±4.7, Fe/Mn=30.3±2.4, n=12); plagioclase (An_91.6±1.1Or_0.3±0.1, n=8).

Classification: HED achondrite (polymict eucrite breccia). Based on Fe/Mn ratios of pyroxenes, sample is an HED. Based on Mg# and Fs contents of pyroxenes, lithic clasts and mineral fragments are derived from basaltic cumulate eucrites.

Specimens: Fabien Kuntz holds the main mass. A polished thin section, an end cut and several fragments weighing a total of 31.67 g.