Mesosiderite — B4  Timbuktu, Mali (16°47’23”N, 3°0’15” W)

Lot Description:
The meteorite’s external surface delimits this irregular complete slice. The cut and polished face reveals a mixture of segregated russet-bronze silicates, iron-nickel flakes & nodules and centimeter-sized yellow-green pyroxene aggregates. A prominent nodule of iron-nickel in the upper-left quadrant enlivens the form. Modern cutting.
109 x 83 x 3mm (4.25 x 3.25 x 0.1 in.)
84.68g

A fine example of an enigmatic meteoritee. Following a scientific analysis of a sample of a new meteorite, a committee of scientists on the Nomenclature Committee of the Meteoritical Society agree on an official name. Meteorites are named after the places to which they have been “delivered”. The meteorite from which this complete slice is derived originated in the asteroid belt between Jupiter and Mars and landed outside of Timbuktu, Mali. In 2015 it was found by a local resident. A Moroccan meteorite dealer happened to be visiting Timbuktu, recognized the rock as a meteorite and bought it from the finder. Mesosiderites are a class of stony-iron meteorites that consist of roughly equal parts of metallic nickel-iron and silicate. There are only four mesosiderites with the B4 designation, which reflects the abundance of minerals and the degree of recrystallization. Unlike pallasites, which formed at the boundary of the stony mantle and molten core of an asteroid that was later disrupted by a collision, the formation of mesosiderites is less well understood. One leading model is that this material formed when the semi-molten core of one asteroid collided with the solidified basalt-strewn surface of a larger asteroid.

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.