Northwest Africa 8575 (NWA 8575)

Morocco

Purchased: May 2014

Classification: Ordinary chondrite (L/LL3)

Geochemistry: Ferroan olivine contains 0.04±0.03 wt.% Cr₂O₃; Kamacite: 1.1±0.1 wt.% Co (n=10) Other elements (P, Cr, Si) are below the detection limit.; The olivine Cr₂O₃ content suggests a subtype of 3.2 or higher according to the diagram from Grossman and Brearley (2005).

Classification: A few porphyritic chondrules contain small amounts of isotropic colorless glass, suggesting a subtype of 3.5 or lower. So the subtype should be between 3.2 and 3.5. The low mean olivine content is in the H range, but this does not matter because the standard deviation is so high. There is also no peak at the mean value, only a continuum of olivine Fa values. According to Rubin (1990), the kamacite Co contents of L chondrites are 0.70-0.95 wt.%; those of LL chondrites are 1.42-37.0 wt.%. The value in this meteorite is in between these ranges, suggesting it is L/LL. The meteorite contains fairly large chondrules, mostly between 400 and 600 μm in diameter, consistent with either an L or LL classification.