“Black Beauty” is the nickname given to a unique, shiny black Martian meteorite that was recovered in the Sahara in 2011 as well as the other matching specimens which were part of the same event. The formal name of the meteorite is Northwest Africa (NWA) 7034. As is the case with lunar meteorites, Martian meteorites are among the rarest substances on Earth. Less than 300Ibs of Martian meteorites are known to exist and Black beauty is more rare still as it doesn’t fit into any of the groups previously used in the nomenclature of Martian meteorites. In scientific literature it is the sole “Martian, basaltic breccia” and it is also the second oldest Martian meteorite known having been formed from a magma more than two billion years ago.
The rock contains relatively large crystals of the minerals plagioclase (a calcium-aluminum silicate) and pyroxene (a calcium-magnesium-iron silicate); these grains crystallized slowly as the magma cooled deep beneath the surface of Mars. The large mineral grains are surrounded by fine-grained material that formed from a quickly cooled magmatic liquid, probably during a volcanic eruption. Rock and mineral fragments were incorporated into the liquid during the eruption, giving the rock a brecciated (i.e. fragmental) appearance. Black Beauty is also unusual in that it contains 10-30 times more chemically bound water than other Martian meteorites, probably a reflection of the water-rich magma from which it crystallized.
This particular specimen of Black Beauty also possesses a membership in another rare class of meteorites: it’s oriented, which is to say that unlike most meteorites, this meteorite did not tumble or invert as it descended through Earth’s atmosphere. Largely as a result of the distribution of its mass and its angle of entry into the atmosphere, it simply plunged to Earth. The parabolic "heat shield" curvature seen here was naturally sculpted by frictional heating.
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