Beschreibung:

Lunar achondrite (monzogabbro) Rissani, Morocco This is a notable offering of a rare, scientifically authenticated lunar meteorite—that is to say, a piece of the Moon ejected from the lunar surface following an asteroid impact which later landed on Earth. (It might be noted that the craters of the Moon are impact craters formed by asteroids and comets.) The most common minerals found on Earth’s surface are not found on the Moon; the minerals comprising the Moon’s crust are limited and readily identifiable. The scientific journal of record, the Meteoritical Bulletin, acknowledges less than 150 pounds of lunar meteorites known to exist, making this among the most exotic substances known. NWA 4734 is the 4734th meteorite classified by scientists following its recovery from the Northwest African (NWA) corridor of the Sahara Desert. It was identified by specific geological, mineralogical, chemical and radiation signatures. NWA 4734 was purchased from desert nomads in Erfoud, Morocco by a meteorite dealer. As a result of its exotic and unusually coarse-grained pryoxene and plagioclase-rich matrix, this specimen boasts an especially rare monzogabbro subclassification. Two dark seams of impact melt are featured in this specimen along with a rim of fusion crust. Fascinatingly, there are two other lunar meteorites—one found on the LaPaz Icefield in Antarctica—which are geochemical and petrographic matches with NWA 4734. In effect, NWA 4734 is one of three meteorites that originated from precisely the same place (and the same impact event) on the Moon that individually found their way to Earth. With a Macovich Collection provenance and accompanied by a copy of the Meteoritical Bulletin describing NWA 4734, this is a choice example of an unusual piece of the Moon. Measures 43 x 25 x 4mm (1.75 x 1 x 0.2 inches) and 7.44 grams.