Large numbers of point defects were produced by the room‐temperature bombardment of LiF by 100‐kV oxygen ions. Clusters of these defects were studied in the electron microscope by means of their diffraction effects and their appearance in bright‐field and dark‐field images. Platelets of polycrystalline lithium were observed to form on {100}LiFplanes. The mechanism of formation of these precipitates is discussed.