Aluminium nitrate and silicic acid were used for the synthesis of aluminosilicate precursor powder of mullite by colloidal process. Copper ions were used in different concentration as sintering additive to the synthesized precursor powder. The compacted powder mixes were sintered at different elevated temperatures. The influence of copper ions on the sintered samples was investigated by the measurement of different physico-mechanical properties, like bulk density, porosity, flexural strength and fracture toughness. The microstructure and phase analysis of the sintered masses were carried out by scanning electron microscopy and XRD analysis. It was observed that copper ions exhibited positive effect on the densification and development of mullite phase in the sintered compacts.