An experimental investigation was carried out on the spontaneous growth of beta -SiC crystals in the Al-C-Si ternary system under atmospheric pressure. Isothermal experiments were performed at temperatures ranging from 730 to 1200 degreesC and with Al-Si melts containing 10 to 40 at% of silicon. The size and shape of the crystals spontaneously grown from these melts strongly depended on the temperature and Si content. Well faceted crystals up to 100 mum were obtained under optimal conditions. Results are discussed for further transposition toward epitaxy experiments.