NWA 17851 ( 24,920 g )

Northwest Africa 17851 (NWA 17851)
(Northwest Africa)
Purchased: 2025 Jun
Classification: HED achondrite (Eucrite, melt breccia)
History: The meteorite was purchased from a Moroccan dealer on the meteorite fair in Ensisheim, France.
Physical characteristics: Dark grayish rock with some fusion crust.
Petrography: Breccia composed of up to 2.5 mm sized lithic clasts and up to 1 mm sized mineral fragments in abundant melt rock matrix recrystallized to pyroxene and often lath-shaped plagioclase. Main minerals are zoned pyroxenes and calcic plagioclase. Minor phases include Ca-pyroxene, olivine, silica, chromite, ilmenite, FeS, and FeNi metal. Contains shock melt veins.
Geochemistry: zoned low-Ca pyroxene: Fs39.4±3.9Wo3.4±0.9 (Fs31.9-44.6Wo1.8-5.4, FeO/MnO=29-36, n=14); Ca-pyroxene: Fs18.5±0.6Wo44.5±0.4 (Fs17.3-19.5Wo44.0-45.2, FeO/MnO=25-31, n=7); olivine: Fa42.8±0.2 (Fa42.5-43.0, FeO/MnO=52±2, n=7); calcic plagioclase: An89.3±3.7 (An80.3-91.9, n=7)
 
Place of purchase: Ensisheim, France
Date: P 2025 Jun
Mass (g): 252
Pieces: 1
Class: Eucrite-melt breccia
Shock stage: high
Weathering grade: moderate
Fayalite (mol%): 42.8
Ferrosilite (mol%): 39.4; 18.5
Wollastonite (mol%): 3.4; 44.5
Classifier: A. Greshake, MNB
Type spec mass (g): 22.9
Type spec location: MNB
Main mass: Hanno Strufe
Comments: Submitted by Ansgar Greshake