With the interference-contrast-microscope it is possible to observe low steps which occur on a GeS-cleavage face during evaporation. The surface evaporates at locations where the crystal structure is disturbed: at the cleavage steps and at distinct dislocations. At first the cleavage steps are completely evaporated if they are not oxidized. Subsequently terraced pits are formed. Steps spread from the center of the pits over the surface homogeneously. The origins of the steps are locally fixed (at dislocations) or appear at random locations when the steps are formed by dislocation loops or by stacking faults. The shape of the pits is rhombic at low temperatures and oval at high temperatures. In addition, rectangular pits randomly appear at different locations at high temperatures. With increasing temperature stationary rhombic step patterns appear temporarily dendritic. Herringbones are formed by intersecting steps of different stationary centers. Precipitated impurities (GeS[2]) affect the spreading steps if the surface deviates from the ideal cleavage plane. Many details of the step patterns are explained by still pictures which show chemically etched examples. A ball model and an animation illustrate the relation between evaporation patterns and the crystal structure.