A rectangular pattern of fine striations appearing when a slice of hexahedrite iron meteorite is cut, polished, and etched with dilute nitric acid; also called Neumann bands. The pattern is aligned along the faces of a cube. Neumann lines are produced by compressional shock waves. Although most obvious in hexahedrites, Neumann lines are present in other iron meteorites as well. They are named after their discoverer, the German mineralogist Franz Ernst Neumann (1798–1895).