Hexahedrite

Hexahedrites are a type of iron meteorite. They are composed almost exclusively of the nickel-iron alloy kamacite, and are lower in nickel content than the Octahedrites.

The name comes from the cubic (i.e. hexahedron) structure of the kamacite crystal. After etching, hexahedrites do not display a Widmanstätten pattern, but they often do show Neumann lines: parallel lines that cross each other at various angles, and are indicative of impact shock on the parent body. They are named after Franz Ernst Neumann, who discovered them in 1848.

Chemical classification

Concentrations of trace elements are used to separate the iron meteorites into chemical classes, which correspond to separate asteroid parent bodies:

• IIAB iron meteorites (includes also some octahedrites)
• IIG iron meteorites (includes also some octahedrites)