from The Meteoritical Bulletin, No. 110
Northwest Africa 14258 (NWA 14258)
Lunar meteorite (feldspathic breccia)
Physical characteristics: A single stone without fusion crust and some caliche on its surface. The interior appears medium gray with small dark and whitish clasts.
Petrography: (K. Metzler, IfP) Fine-grained polymict achondritic breccia, consisting of small lithic clasts (up to 7 mm) and mineral fragments (mainly plagioclase, olivine, and pyroxene) set in a compacted fine-grained clastic matrix of related debris. The clastic matrix is intermingled with small amounts of crystallized vesicular melt. Lithic clast types: fine-grained subophitic basalt, olivine gabbro, fragment-rich impact melt rock, and impact glass. Accessories are ilmenite, chromite, troilite, and Ni-bearing metallic iron (~Fe93Ni7).
Geochemistry: Mineral compositions and geochemistry: Mean olivine composition: Fa31.9±7.8 (Fa21.4-42.6); Fe/Mn (at.): 96.4±23.4 (62-122); n=10. Mean pyroxene composition Fs23.1±4.3 Wo4.1±1.2 (Fs18.0-29.9 Wo2.6-6.3); Fe/Mn (at.): 55.0±13.2 (42-75); n=6. Plagioclase An97.0±0.8 (An95.5-98.1); n=13. Chemistry of an impact glass spherule (wt%): SiO2=44.3; Al2O3=27.4; CaO=16.1; FeO=5.3; MgO=5.1; Na2O=0.5; TiO2=0.4; Cr2O3=0.2; MnO=0.08.
Classification: Lunar feldspathic breccia.
Specimens: 20 g at Institut für Planetologie, Münster, Germany.
Randy Says…I have not studied Northwest Africa 14258.
Meteoritical Bulletin Database