Abstract: Exposure of transparent MgAl 2O 4 ceramics to 60 Co γ rays and to the electrons beam with energy 1.7 MeV introduce decrease of transmittance and change of the color of the transparent MgAl 2O 4 ceramics. They are due to V type absorption centered at 390 nm. Although γ rays and electrons induce the same phenomenon in MgAl 2O 4 ceramics, there is a great deal of difference of the microcosmic interaction mechanism between them. Possible reason for this difference is discussed.