Editing Dislocation (section)

==== Chemical etching ====
When a dislocation line intersects the surface of a metallic material, the associated strain field locally increases the relative susceptibility of the material to acid [[industrial etching|etching]] and an [[etch pit density|etch pit]] of regular geometrical format results. In this way, dislocations in silicon, for example, can be observed ''indirectly'' using an interference microscope. Crystal orientation can be determined by the shape of the etch pits associated with the dislocations.

If the material is deformed and repeatedly re-etched, a series of etch pits can be produced which effectively trace the movement of the dislocation in question.