Glass series (20-x)Y2O3-xMnO(2)-20Al(2)O(3)-40SiO(2)-20CaO (x = 5, 10, 15 and 20, mol%) have been synthesized by melt quench technique followed by sintering at 850 degrees C. The optical band gap of the samples is in wide semiconductor range and increased with MnO2 content. Photoluminescence study exhibits emission in Mn2+ d-states. On the other hand, hardness decreases with MnO2 content except for 10 mol% MnO2 containing glasses (YM10). The formation of braunite phase in glass ceramics induces capacitive losses. In lower temperature region, the conductivity behaviour of samples follows superlinear power law. In higher temperature region, it follows the universal law of conduction. The dielectric constant for the sintered glasses is constant with respect to temperature, approximately upto 350 degrees C and 1 MHz frequency. Above 350 degrees C, the ionic conduction dominates in all the sintered glasses. The anomaly in properties is observed when the ratio of Y2O3/MnO2 is 1:1.