Similar to lot 39 which immediately follows. Dronino is classified as an ungrouped iron. In terms of its composition, it is unlike any other iron meteorite and does not fit into any of the established chemical (compositional) groups. When there are no other ungrouped meteorites with the same chemical composition, we are in the presence of the sole representation of a previously unsampled asteroid. Dronino is the only known sample of what was at one time a protoplanet in our solar system (an asteroid with a differentiated core, mantle and crust).

Iron meteorites are primarily composed of two different iron-nickel alloys, kamacite and taenite. In Dronino, the kamacite contains 7% nickel while rare grains of taenite contain 26%. The banded and elongated accents seen are sulfide inclusions. While there is no other meteorite that has the surface texture of Dronino, the same can be said for the features seen in a cut sample. If lots 28 and 39 were cut — which should never be the case — they would exhibit a similar internal structure, but almost certainly not as sublime as the specimen now offered of a meteorite that is the sole representative of a protoplanet which no longer exists.

Christie's would like to thank Dr. Alan E. Rubin at the Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles for his assistance in preparing this catalogue.

89 x 54 x 2mm (3.5 x 2 x 0.1 in.) and 80.9g (0.2 lbs)