A porcelain blank comprising a porcelain composition for dental restorations comprising a leucite crystallite phase and a glass matrix phase, wherein the leucite crystallites possess diameters not exceeding about 10 micron. Preferably, the porcelain composition has a maturing temperature from about 750.degree. C. to about 1050.degree. C. and a coefficient of thermal expansion from about 9.times.10.sup.-6/.degree. C. to about 17.5.times.10.sup.-6/.degree. C., and comprises: TABLE-US-00001 SiO.sub.2 57-67 Al.sub.2O.sub.3 7-15 K.sub.2O 7-15 Na.sub.2O 6-15 Li.sub.2O 0.5-3.