The (111) surface of a single gold crystal was bombarded by monoenergetic ion beams of 1H, 4He, 11B, 14N, 20Ne, and 40Ar in the energy range 10–60 keV. The total positive charge liberated from the crystal surface under the ion bombardment was studied as a function of crystal orientation. The yield showed strong minima when the ion beam entered the crystal along the low index directions. The angular full width at half depth of these minima was studied as a function of energy and atomic number of the projectiles. The results are in good agreement with a theory based on a 1/R2 ion-atom potential.