NWA 13854 (22,488 g)
Northwest Africa 13854 (NWA 13854)
History: The meteorite was purchased from a dealer in Morocco.
Physical characteristics: Dark brownish fragment without fusion crust.
Petrography: The meteorite displays a light brownish interior and consists of silicate (about 60 vol%) and metallic (about 40 vol%) portions. The silicate fraction is largely composed of low-Ca pyroxene up to 8 mm (sometimes weakly compositionally zoned) and angular calcic plagioclase grains up to 1 mm. Ca-pyroxene is present as blebby and lamellar exsolutions in low-Ca pyroxene. Plagioclase often poikilitically encloses smaller pyroxene grains. Sparse olivine show reaction coronas with pyroxene and contain symplectitic orthopyroxene-chromite inclusions. Minor phases are silica, Ti-chromite, ilmenite, FeS, and Mg-merrillite. Kamacite and taenite constitute the metallic portion and are present as up to 6 mm sized irregular shaped aggregates dispersed throughout the rock.
Geochemistry: low-Ca pyroxene: Fs29.3±0.6Wo4.5±0.2 (Fs28.6-30.3Wo4.2-5.0, FeO/MnO=24-27, n=10); augite exsolutions: Fs16.5±0.6Wo39.0±0.9 (Fs15.9-17.6Wo37.1-39.8, FeO/MnO=19-21, n=9); olivine: Fa32.4±0.4 (Fa31.7-33.1, FeO/MnO=41±2, n=11); calcic plagioclase: An86.5±3.4 (An83.3-92.8, n=11)
|Place of purchase:||Morocco|
|Ferrosilite (mol%):||29.3; 16.5|
|Wollastonite (mol%):||4.5; 39.0|
|Classifier:||A. Greshake, MNB|
|Type spec mass (g):||23.7|
|Type spec location:||MNB|
|Main mass:||Philippe Schmitt-Kopplin|
|Comments:||Submitted by Ansgar Greshake|