.31" Ungrouped Achondrite Meteorite (.16 g) Fragement - NWA 6704

The NWA 6704 Ungrouped Achondrite Meteorite

NWA 6704 is the name given to a single, dense, yellowish-green stone that was found in pieces in Algeria, Northwest Africa. The reassembled 42 pieces (plus some granular debris) fit together as a single ovoid mass weighing 8387. It featured rounded, shiny exterior surfaces and small patches of remnant black fusion crust. The very fresh interior is mostly pale yellow-green with sporadic darker brownish grains and sparsely distributed tiny grains of opaque oxide and silvery metal. It wasn't a witnessed fall and the find date was not recorded, however the purchase date is February of 2011.

This specimen is unlike other achondrites in its combined features: relatively ferroan mafic silicate minerals with elevated FeO/MnO ratios and anomalous nickel contents, extremely sodic plagioclase, very nickel-rich metal, and oxygen isotopic composition that plots within the field for acapulcoites-lodranites. Weathering is low and limited to minor coatings of pale orange desert dust on broken surfaces.

Meteoritical Bulletin: Entry for NWA 6704

Achondrites are a type of stony meteorite that lacks chondrules--round grains that aggregate from molten or partially molten droplets in space to form chondrites. Achondrites still contain grains, but their textures are extremely distinct and analogous with igneous processes rather than the chondrule-producing conditions at the beginning of the solar system.

Achondrites make up about 8 percent of all known meteorites. They are almost all regolith breccias, ejected from impacts on larger asteroids and sometimes the moon and Mars. Most are HED (howardite-eucrite-diogenite) in composition, sourced from the asteroid Vesta: it is the second largest asteroid in the Solar System and the only asteroid visible to the naked eye.