Sanitary wares were prepared from rhyolite lava and red syenite replacing k-feldspar in the ceramic batches. quartz, albite, microcline and anorthoclase minerals were identified in the k-feldspar, rhyolite and syenite rocks. The thermal behavior indicated that the softening temperatures were 1202°c for k-feldspar,1208°c for rhyolite and 1178°c for red syenite whereas the melting points were 1309°c for k-feldspar,1312°c for rhyolite and 1303°c for red syenite. After sintering the batches at 1200°c/20 h, quartz with mullite was developed in sanitary ware containing k-feldspar, but in that consisting of rhyolite lava or red syenite sillimanite was developed. The microstructure of sintered samples produced with rhyolite lava and red syenite replacement shows irregular pattern containing submicron and nano-size particles. For physicals testes, samples treated at 1200 °c/20h gave nearly similar values. The coefficient of thermal expansion (CTE) which refers to the rate at which a material expands with the increase in temperature at 800 °c were 5.29 x 10 -6 °c-1 for k-feldspar containing body, 6.84 x 10-6 °c-1 for rhyolite and 5.7 x 10-6 °c-1 for red syenite based ones. The modulus of rupture for samples before firing were 34.9 kg/cm2 for k-feldspar, 34.3 kg/cm2 for rhyolite and 33.57 kg/cm2 for red syenite and their corresponding sintered samples after firing at 1200°c/20 h were 482.87 kg/cm2 for k-feldspar, 445.27 kg/cm2 for rhyolite and 481.6 kg/cm2 for red syenite because of solidification. The ratio of water absorption values were 0.29% for k-feldspar, 0.33% for rhyolite and 0.19% for red syenite, while the shrinkage ratios were 10.3% for k-feldspar, 10% for rhyolite and 10.83% for red syenite The present characteristics and properties indicate that both rhyolite lava and red syenite are suitable for the replacement of k-feldspar in sanitary body.