Haxonite
Haxonite is an iron-nickel carbide found in some iron meteorites and in metal grains of primitive chondrites.
Haxonite is a carbide of iron and nickel, roughly (Fe,Ni)23C6. It was first described in 1971 from iron meteorites and named after Howard J. Axon, a British metallurgist who studied meteoritic metal.
Haxonite differs from cohenite, the other main meteoritic carbide, in containing more nickel and having a different crystal structure. It typically forms in metal that is richer in nickel. It is known from several IAB iron meteorites and from the metal grains of some unequilibrated ordinary chondrites and CR chondrites, where it is thought to have grown when carbon-bearing gases or fluids reacted with metal at moderate temperatures.
Like most meteoritic carbides, haxonite is identified with a polished section, reflected light and microprobe analysis. Its presence tells researchers that the metal was exposed to carbon in an environment almost without oxygen, conditions that cannot normally exist near Earth's surface.
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