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NWA 6254 (34.40 gram)

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[ Meteoritical Bulletin Database ]


Classification: Chondrite CK3 S1/W-moderate
Place/Time: 01.2009 in Morocco
Mass: 1230g

Petrography: (K. Metzler, IfP) Chondrules and CAIs are embedded into a fine-grained brownish matrix. The matrix consists mostly of equilibrated Fe-rich olivine grains, interspersed with magnetite nodules. The mean apparent chondrule diameter is 1.08±0.44 mm (0.46-2.23 mm; n=54). CAIs up to 0.9 cm are observed. A ~4 cm long vein (confined by the sample size), filled by dark fine-grained material, transects the sample slice.

Geochemistry: The composition of matrix olivine is Fa33.9±0.8 (Fa32-35; n=17), while olivine in chondrule cores retained its original Mg-rich composition. Random olivine measurements revealed Fa30.7±8.3 (Fa0-35; n=21). Low-Ca pyroxene (En89-97 Fs2-10 Wo1-4; n=4) mainly occurs in chondrules. Most pyroxene grains outside of chondrules are Ca-rich (En35-38Fs10-14Wo49-52; n=5). The compositional range of feldspar (n=4) is An15-24. Magnetite is the most abundant opaque phase and shows significant concentrations of elements other than Fe (n=3): MgO 0.5-0.7 wt%; Al2O3 2.8-3.3 wt%; TiO2 0.9-1.1 wt%; Cr2O3 4.1-4.5 wt%; NiO 0.2-0.5 wt%.

Classification: CK chondrite based on mineral chemistry. Petrologic type 3 based on the chemical variation of olivine and pyroxene.