This complete slice contains a mosaic of green pyroxene—which makes up nearly 50% of the mass along with white plagioclase grains (30%) which are intersected by veins of dark-gray shock melt (20%) coursing through the cut face. A single basaltic eucrite lithology is evident, as are vesicles in the impact melt and terrestrial tinting from a long residency in the Sahara Desert. On the reverse side, a band of the meteorite’s external surface frames the flat face. Modern cutting.
132 x 77 x 6 mm. (5 x 3 x 0.25 in.)

91.4 g.

With a mean diameter of 525 km. (326 miles), Vesta is the second largest asteroid in the solar system. HED meteorites (howardites, eucrites and diogenites) are believed to originate from Vesta in part because Vesta is only large asteroid with a basaltic surface. Vesta is a differentiated body with a metal core, a silicate mantle and a volcanic crust. Spectroscopic analysis as well as gamma-ray and neutron detection data indicate that Vesta’s surface is consistent with the HED class of meteorites. Data transmitted from NASA’s Dawn spacecraft, which orbited Vesta in 2011-12, provided further confirmation. Finally, there are two enormous craters in Vesta’s southern hemisphere that could be the site where Vestan material was launched toward Earth.

The largest single piece of Vesta on Earth, NWA 12587, was discovered in North West Africa in 2014. It weighs 71.74 kg. (158 pounds). Two slices were removed from the specimen, one of which provided the sample for the meteorite to be analyzed and classified. This is the other slice: the largest complete slice from the largest piece of Vesta known to exist…on Earth.

The mass from which this slice was cut, the main mass of NWA 12587, the largest piece of Vesta on Earth, will be on display at the Maine Mineral & Gem Museum.

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.