Northwest Africa 2060

Morocco

Found 2003

Achondrite (howardite)

A 985 g, very fresh stone with shiny fusion crust, was purchased in Rissani, July 2003. Classification and mineralogy (T. Bunch and J. Wittke, NAU): a howardite of unusual characteristics. Fine-grained and powdery, average clast and mineral grain size is < 2 mm with few clasts > 3 mm. Clast modes: diogenites, 74 vol. %; eucrites 20 vol. % (12 % cumulate, 8 % basaltic); anorthositic-like clasts, 3 %; shock melt clasts. 2 %, and opaques, 1%. Diogenite orthopyroxene, Fs_35.6-38.8Wo_2.3-4.2; plagioclase, An ₈₇; chromite, Cr/(Cr+Al) = 0.81; metal, Ni = 0.67 wt %. Melt inclusions in opx contain Ca-rich pyroxene, Fs_33.3Wo_37.5; phosphate, silica phase, and K-rich glass. Plagioclase-pyroxene cumulates, Fs_38.2Wo₂₁; plagioclase, An_86.Other eucrite textures include recrystallized, granular, ophitic, subophitic, and variolitic (Fs_31.6Wo₇ and Fs_61.8Wo_33). Plagioclase-rich clasts have 95 vol.% plagioclase (An_96.1). Mildly shocked; no apparent oxidation or Fe staining. Specimens: 26 g, NAU: main mass. Boswell.