Transparent glass-ceramics (GCs) own interesting optical properties for several photonic applications. The melt-quenching (MQ) method is routinely used to prepare OxGCs but the high melting temperatures (1400-1700°C) greatly affect the fluoride content. Thus, the sol-gel (SG) route appears as a promising alternative to prepare OxFGC films and bulk materials with a much higher active crystal phase content and sintered at much lower temperature than that MQ. LaF3, GdF3 and NaGdF4 nanocrystals are precipitated in pure silica matrices containing up to 30% of active phase with noteworthy optical properties. An alternative procedure to obtain glass-ceramics are being considered based in the preparation of nano-crystalline suspensions and their subsequent dispersion in a sol-gel matrix.