Iron Meteorite — 1CNorth Yilgarn, Western Australia

In a remote, largely inaccessible region in the southwest edge of Australia, the Mount Dooling meteorite was first discovered in 1909 by gold prospector A.P. Brophy. In this select example, large metallic grains appear interwoven in a complex array specific to the IC chemical group. The smallest group of iron meteorites, the IC group contains only eight members. Because different iron meteorites have different compositions and cooled at different rates, they frequently exhibit distinctly different patterns which are diagnostic in the identification of an iron meteorite. The latticework in evidence is indicative of a slow cooling rate that provided sufficient time—millions of years—for the meteorite’s elements to arrange themselves into their crystalline structure. The small amount of nickel in Mount Dooling (about 6%) results in the coarse, more abstract pattern seen here than in a Gibeon meteorite (see lot 10). At some point, after solidifying, Mount Dooling experienced a high-energy impact in interplanetary space; the iron sulfide nodules were melted and the kamacite grains developed shock-produced twin lamellae known as Neumann bands. Some specimens of Mount Dooling are shrapnel-like which suggests a low-altitude explosion or cratering event.