Description
Northwest Africa 13546 (NWA 13546)
(Northwest Africa)
Purchased: 2020
Classification: Lunar meteorite (feldspathic breccia)
History: The meteorite was purchased from a dealer in Morocco.
Physical characteristics: Many small greyish fragments some of which covered with fusion crust.
Petrography: The meteorite displays a grayish interior and is a feldspathic breccia composed of mineral fragments, basaltic, gabbroic, and impact melt clasts cemented by a fine-grained partly shock-melted groundmass. Most abundant minerals are calcic plagioclase, olivine of highly variable composition, and exsolved pyroxene; less abundant are and complex zoned pyroxenes. Accessories include ilmenite, and FeNi-metal. The meteorite contains shock melt veins and pockets.
Geochemistry: olivine: Fa21.3±11.1 (Fa9.9-44.3, FeO/MnO=79±8, n=26); fayalite: Fa95.5±0.2, FeO/MnO=85±3, n=6; low-Ca host to augite exsolution lamellae: Fs49.2±0.6Wo4.3±0.7 (Fs47.8-50.3Wo3.5-5.7, FeO/MnO=56±3, n=11); augite exsolution lamellae: Fs23.3±0.8Wo41.0±0.6 (Fs22.4-25.1Wo39.3-41.5, FeO/MnO=53±6, n=10); complex zoned pyroxene: Fs38.1±10.0Wo21.5±13.8 (Fs25.8-49.6Wo5.6-39.0, FeO/MnO=50±3, n=11); calcic plagioclase: An97.6±0.3 (An97.1-97.9, n=14)
Classification: Lunar meteorite (feldspathic breccia); likely paired with NWA 11273.
Place of purchase:MoroccoDate:P 2020Mass (g):2300Pieces:manyClass:Lunar (feldsp. breccia)Shock stage:moderateWeathering grade:lowFayalite (mol%):21.3; 95.5Ferrosilite (mol%):49.2; 23.3; 38.1Wollastonite (mol%):4.3; 41.0; 21.5Classifier:A. Greshake, MNBType spec mass (g):21.1Type spec location:MNBMain mass:Larbi ChnaouiComments:Submitted by Ansgar Greshake
