The behavior and some physical and thermal properties of a 30Li(2)O-70SiO(2) base glass composition with addition of ZrSiO4 in the as quenched state was investigated with the aid of X-ray diffraction (XRD), differential thermal analysis (DTA), thermal expansion and microhardness measurements, as well as density measurements. Transparent glasses prepared by the addition of ZrSiO4 up to 10.30 mol% were obtained, ZrSiO4 was found to decrease the expansion coefficient of the investigated glasses from 11.0 x 10(-6) to 7.96 x 10(-6)degrees C-1. The glass transition and softening point temperatures of the glasses showed a reverse behavior. On the other hand, both hardness and density increased for successive increases of the ZrSiO4 amounts, with the highest values of 6.3 GPa and 2.65 g/cm(3), respectively.