Neumann lines, or Neumann bands, are fine patterns of parallel lines seen in cross-sections of many hexahedrite

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 nickel concentration in hexahedrites is always below 5.8% and only rarely below 5.3%....

 iron meteorite

Iron meteorite

Iron meteorites are meteorites that consist overwhelmingly of nickel-iron alloys. The metal taken from these meteorites is known as meteoric iron and was one of the earliest sources of usable iron available to humans.-Occurrence:...

s in the kamacite phase, although they may appear also in octahedrites provided the kamacite phase is about 30 micrometres wide. They can be seen after a polished meteorite cross-section is treated with acid. The lines are indicative of a shock-induced deformation of the kamacite

Kamacite

Kamacite is a mineral. It is an alloy of iron and nickel, usually in the proportions of 90:10 to 95:5 although impurities such as cobalt or carbon may be present. On the surface of Earth, it occurs naturally only in meteorites. It has a metallic luster, is gray and has no clear cleavage although...

 crystal, and are presumably due to impact events on the parent body of the meteorite

Meteorite

A meteorite is a natural object originating in outer space that survives impact with the Earth's surface. Meteorites can be big or small. Most meteorites derive from small astronomical objects called meteoroids, but they are also sometimes produced by impacts of asteroids...

.

The lines are named after Johann G. Neumann, who discovered them in 1848 in the iron meteorite Braunau, a hexahedrite

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 nickel concentration in hexahedrites is always below 5.8% and only rarely below 5.3%....

, which fell in 1847.