  We present a solid state system which spontaneously generates remarkable
engraving patterns on the surface of Ge. The layered construction, with a metal
film on the Ge surface, results in coupling of the metal catalyzed etching
reaction with the long range stress field at the Ge - metal interface. The
etching patterns generated have similarities with Turing patterns, hydrodynamic
patterns, crack propagation, and biological form. We describe spirals, radial
patterns, and more disordered structures. Euler buckling of the metal layer
generates a characteristic wavelength for some patterns.
