Fine single crystals of low-melting point materials are prepared by slowly withdrawing a glass crystal growth capillary tube containing the material from a heating apparatus which precisely maintains the molten material at a temperature just above its melting point. Temperature control of the molten material in the crystal growth tube, prior to solidification, is attained by enclosing the crystal growth tube in a temperature control tube containing the molten material being solidified. Preferably, the inside diameter of the temperature control tube is slightly larger than the outside diameter of the crystal growth tube, and both tubes reach into a reservoir of the molten material to be grown as a crystal, so that the molten material is drawn upwardly into the crystal growth tube and the space between the crystal growth tube and the temperature control tube by capillary action.