The Na₂O-B₂O₃-SiO₂ system has been studied for a long period because of some glasses with distinct properties presenting industrial interest.

                This work is proposing to point out some correlations between the properties of some glasses of this system and the basicity amount (pB).

                Three glasses with different compositions have been synthesized and for each the following properties, were measured: the dilatation coefficient (α·10^-7), the vitreous transitions temperature (T_g), the dilatometer softening temperature (M_g), the refraction index (n), the density (d) and the chemical stability.

                The experimental data have pointed out a strong dependence between properties and basicity, showing the structural parameter role, that the basicity has.

                Also, the results obtained for the synthesized glasses were compared with the results reported in literature for glasses of similar compositions.