This somewhat triangular end piece reveals both the interior and exterior surfaces of a Moon rock. Sahara Desert hues accent the external surface. While one corner exhibits steep slopes from a singular ridge, the exterior more typically slopes gently to its edges. The classic characteristics of a feldspathic lunar breccia are exhibited: white anorthositic rocks suspended in a charcoal lunar groundmass “cemented” together as part of an impact melt that solidified. The low average concentrations of FeO and Th indicated this lunar sample originated in the feldspathic lunar highlands. Its primary minerals are anorthite, olivine, pigeonite, augite, pigeonite, fayalite, silica, ilmenite and kamacite. The cut and polished face reveals the same lithology as the exterior in a finer resolution. The brecciation seen is the result of the ongoing bombardment of the Moon’s surface by asteroid impacts prior to the collision responsible for launching this Moon rock to Earth. Modern cutting.
199 x 122 x 19 mm. (7.75 x 4.75 x 0.75 in.)

537.9 g. (1.2 lbs.)

Material from the Moon is among the rarest substances on Earth. Less than 600kg. of lunar meteorites are known to exist. All would fit within four foot lockers and a significant portion is controlled by governmental institutions. While Apollo astronauts returned with less than 400kg. of Moon rocks, not one milligram of this material is available for private ownership. The following two lots are portions of the same Moon rock, NWA 12691 (provisional), recently recovered in the Sahara Desert. Scientists identify Moon rocks by their specific textural, mineralogical, chemical and isotopic signatures. Many of the common minerals found on Earth’s surface are rare or absent on the Moon and some lunar minerals are unknown on Earth. In addition, Moon rocks contain gases captured from the solar wind with isotope ratios very different from the same gases found on Earth. Lunar meteorites arrived on Earth after having been blasted off the lunar surface by the collision of an asteroid. In fact, collisions of asteroids and comets created the Moon’s large craters. This particular meteorite was part of a large meteorite shower straddling the Mauritanian and Algerian borders and is responsible for nearly half of the lunar meteorites known. Approximately 30 different meteorites have been collected, analyzed, classified and assigned different NWA numbers in the belief they might be from different events and represent different lunar samples—but it has been determined that they all originate from the same lunar impact event as the current offering, NWA 12691 (provisional). As NWA 8046 was the first of these specimens, the meteorites belonging to this event are referred to as being part of the NWA 8046 clan. This lunar sample is the end cap of the following lot. As one would expect, many of the Moon rocks returned by Apollo missions are nearly identical to lunar meteorites—and such is the case here.

Christie's would like to thank Dr. Alan E. Rubin at the Institute of Geophysics and Planetary Physics, University of California, Los Angeles for his assistance in preparing this catalogue note.