Abstract: Ceramics with a glaze applied to the surface of ceramic blank, the bending strength of which ceramic blank is 100 Mpa or higher or the firing shrinkage rate is 7% or higher and the porosity is 7.5% or higher.

Abstract: A method for preparing high strength and high thermal shock-resistant china for ceramic whiteware which comprises the steps of molding a china-forming raw material which mainly comprises a natural ore material capable of forming corundum through firing or a material obtained by calcining the natural ore material to form corundum, a natural ore material capable of forming mullite through firing or a material obtained by calcining the natural ore material to form mullite, a clayey material and a flux such as feldspar, nepheline or dolomite; and then firing the molded china-forming raw material. The method permits the production of cheaper china for ceramic whiteware having high strength and excellent thermal shock resistance as compared with those prepared by the conventional techniques.

Abstract: A vitreous china comprises, as principal components, 25 to 70% by weight of a glass phase and 75 to 30% by weight of a crystalline phase, the glass phase comprising, as principal chemical components, 4 to 12% by weight of K.sub.2 O+Na.sub.2 O, 50 to 75% by weight of SiO.sub.2 and 17 to 40% by weight of Al.sub.2 O.sub.3 while the total amount of the glass phase is defined to be 100% by weight, and the crystalline phase comprising, as principal mineral components, 10 to 60% by weight of .alpha.-alumina, 0 to 20% by weight of quartz and 2 to 20% by weight of mullite while the total amount of the vitreous china is defined to be 100% by weight. The vitreous china and the method for preparing the same may permit the marked improvement of the mechanical strength of the vitreous china. The mechanical strength may be improved without adversely affecting other physical properties (such as high temperature deformation, resistance to thermal shock and firing temperature).