Several silicates, including α-quartz, zirconium silicate, thorium silicate, LiAlSiO4, a silicate glass and several nitrides, α and β Si3N4, AlN, ZrN as well as Si2N2O and ThO2, have been irradiated by 1019-1021Krypton(3MeV)ions/m−2The damaged powders of original particle size less than 5 μm, have been examined by x-ray diffraction and electron microscope methods. The silicates and Si2N2O become non-crystalline by 10 × 19 ions/m2. The particles change shape, extending and bloating under prolonged irradiations of the order of 100 × 1019ions/m2. Silicate glass also undergoes this irradiation creep process. The nitrides and ThO2behave quite differently and even at fluences of 200 × 1019ions/m−2the powders remain crystalline, retaining relatively sharp edges to the particles without exhibiting irradiation creep. This difference in behavior can be related to the nature of the framework crystal structures, flexible for the silicates with variable bond angles, rigid for the nitrides with fixed bond angles. This may explain the behavior of radioactive minerals not found in a metamict condition.