The effect of varying B2O3 content on the crystallization and microstructure behavior of barium-containing glasses based on the system BaO center dot 4MgO center dot Al2O3 center dot 6SiO(2)center dot 2MgF(2) was investigated by differential thermal analysis (DTA), X-ray diffraction, and scanning electron microscopy. Heat treatment of glass specimens in the form of fine powders in the range of 884 degrees C901 degrees C led to the formation of barium fluorophlogopite. DTA study revealed that the glass transition temperature (T-g) and crystallization peak temperature (T-p) decreased by increasing B2O3 content. It was also found that the higher the B2O3 content, the higher the aspect ratio of fluorophlogopite crystal.