Moon rock, lunar feldspathic breccia, North West Africa
NWA 12691, is the 12,691st meteorite to be recovered from the North West African grid of the Sahara Desert and then analyzed by a team of scientists, which then underwent peer review prior to publication in the scientific journal of record, the Meteoritical Bulletin.
While meteorites are rare — the weight of every meteorite known is less than the world’s annual output of gold — and lunar meteorites represent just 0.8% of all meteorites. There are less than 1000 kg of lunar meteorites (pieces of the Moon ejected off the Moon’s surface as a result of an asteroid impact) known to exist and all would fit in the back of a pick-up truck, and a good deal of this material is already in museums and research institutions.
Scientists are readily able to identify Moon rocks by analyzing a rock's texture, mineralogy, chemistry and isotopes. Moon rocks also contain gases from the solar wind, and those gases have different isotope ratios than terrestrial rocks. This chunk of the Moon is a lunar breccia; it contains lot of different fragments of different lunar materials 'cemented' together as a result of the pressure and heat generated from repeated impacts on the lunar surface. The prominent white clasts seen is anorthite, which is very rare on Earth but not on the Moon. The scientist who did the analysis, Dr. Anthony Irving, has an international reputation for classifying meteorites.
NWA 12691 looks exceedingly similar to some of the Moon rocks returned to Earth by the Apollo missions. The cut and polished surface of this pocket-sized specimen reveals angular shards of signature anorthite adrift in dark lunar regolith. The highly textured reverse reveals the same but not with the same resolution as its polished counterpart. Now offered is one of the rarest objects on Earth…the Moon.
27 x 40 x 9mm (1 x 1.5 x 0.33 in.) 15.38 grams (76.5 carats)
The analysis of this meteorite was led by Dr. Anthony Irving, among the world’s foremost meteorite classification experts. The classification was published in the 108th edition of the Meteoritical Bulletin — the official registry of meteorites — which accompanies this offering.
