High strength feldspathic porcelain

High strength feldspathic porcelain with an unglazed bending strength of greater than 1,800 kg/cm.sup.2, the porcelain consisting essentially of 22-85% by weight of SiO.sub.2, 18.8-73% by weight of Al.sub.2 O.sub.3, not greater than 1.5% by weight of Fe.sub.2 O.sub.3, not greater than 1.5% by weight of T.sub.i O.sub.2, not greater than 0.7% by weight of CaO, not greater than 0.5% by weight of MgO and 1.5-6.5% by weight of at least one oxide selected from the group consisting of K.sub.2 O and Na.sub.2 O;

• the porcelain having a crystal phase formed from corundum in an amount of 20-60% by weight and at least one second crystal phase selected from the group consisting of mullite, cristobalite, and quartz, a total degree of crystallinity of said second crystal phase being greater than 40% by weight, a degree of crystallization for said at least one second crystal phase being selected in ranges of 5-50% by weight for mullite, not greater than 40% by weight of cristobalite, and not greater than 10% by weight for quartz, a grain size of said crystal phases being not greater than 20 .mu.m, and a size of defects in said porcelain being not greater than 40 .mu.m.