Neumann lines, or Neumann bands, are fine patterns of parallel lines seen in cross-sections of many hexahedriteiron meteorites 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 crystal, and are thought to be due to impact events on the parent body of the meteorite.[1]
Iron meteorite showing relatively homegenous crystal formation with hexadedrite lamellae line, 1901