Turbulent free convection of the melt during growth of calcium fluoride crystals by the Czochralski technique has been observed visually and by thermocouple measurement of the attendant temperature fluctuations. Such fluctuations, on the order of 30°C, were shown to cause growth rate fluctuations, and explain the origin of some of the striations previously observed in Czochralski‐grown semiconductor crystals. Effects of operating variables on the turbulence were measured. The best method for reducing or eliminating the turbulence was shown to be reduction of the vertical temperature gradient by use of reflectors or after‐heaters around the crystal.