Moon rock, lunar feldspathic breccia, North West Africa
This specimen is extremely similar to the other lunar meteorites offered: it’s part of the NWA 12691 event — but larger.
Meteorites are rare; the weight of every meteorite known is less than the world’s annual output of gold. Lunar meteorites, i.e., pieces of the Moon ejected off the Moon’s surface as a result of an asteroid impact — and nearly all of the craters on the Moon are the result of such impacts — are far more rare still. There are less than 1000 kilograms of lunar meteorites known to exist and all would fit in the back of a pick-up truck. A good deal of this material is untouchable to the public as it’s in museums and research institutions. Every milligram of the nearly 400 kilograms of Moon rocks returned to Earth from NASA’s Apollo missions are also off-limits to the public.
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, which means 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.
For a meteorite to be “official” it must be published in the Meteoritical Bulletin, the scientific journal of record. The scientist who did the analysis of this lunar sample, Dr. Anthony Irving, has an international reputation for classifying meteorites, but prior to publication his analysis must first be peer reviewed by scientists on the Nomenclature Committee of the Meteoritical Society before coming up with a name. Meteorites are named after the places from where they are recovered, a geological feature or name of a town or county, but if found in the desert where there are no features, meteorites are given the names of the delimited desert grid where it was found followed by a sequential number. So, NWA 12691 is the 12,691st meteorite to be recovered, analyzed and approved for publication recovered from the North West African zone of the Sahara Desert.
NWA 12691 is extremely similar to some of the Moon rocks returned to Earth by Apollo missions. Angular shards of signature anorthite of all sizes are adrift in dark lunar regolith. The breccia seen is the result of the ongoing pulverization of the Moon from repeated asteroid impacts until one such impact ejected this piece off the Moon into space. This specimen features a rarity: a centimeter-sized highly magnetic globule of iron from one such impactor protruding from its side. Among the rarest objects on Earth, this is a quintessential specimen of the Moon.
93 x 131 x 63mm (3.66 x 5 x 2.5 in.) and 967.7 grams (2 lbs)
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.
Provenance: Dr. Lawrence T. Stifler Collection of Meteorites
