Abstract: Ceramic moldings containing finely crystalline cordierite are described, which are obtainable by the intensive grinding of precrystallized cordierite powder, mixing the powder with second additive phases of higher modulus of elasticity, shaping the mixture, and sintering the greenware thus obtained in a siliceous atmosphere at temperatures between 900.degree. and 1400.degree. C. The moldings according to the invention have not only good mechanical strengths but also outstanding dielectric and thermal properties; they are therefore especially suitable for use as dielectrics and as thermal insulating components.