The nucleation and crystallization of Li2O-Al2O3-SiO2 glasses doped with 0, 0.4, 0.8 and 1.2 wt.% F- were investigated. With increasing fluoride content. the transformations from glass to beta-quartz solid solution (beta-quartz) and beta-quartz to beta-spoclumene solid solution (beta-spodumene) appeared at lower temperatures. The crystallization peak temperature (T-p) and activation energies (E) decreased, the Avrami exponent (n) and pre-exponential factor (nu) increased. The results suggest that fluoride promotes the initial crystallization and diffusion in the glass. (C) 2003 Elsevier B.V. All rights reserved.