Evidence of slip in calcium fluoride single crystals

Natural single crystals of calcium fluoride have been cleaved along (111) planes and the cleavage faces have been etched in 0.2 N nitric acid solution. Etching produces rows of equally spaced etch pits running in <110>directions. One‐to‐one correspondence of glide bands has been established on the matched faces and on the three different flakes of the same crystal. This is further confirmed by studying the rosette structure produced on a (111) cleavage plane by indenting that plane itself. The active slip planes are found to be {110}. The implications are discussed.