The properties of electrofused spinel and periclase powders prepared by different milling techniques are reported. Vibratory milled specimens display a higher structure imperfection of the surface, and the amorphous surface layer differs compositionally from the percursor material. In the pulverized products, contaminating elements (Na, Si, and, to a lesser extent, Fe) tend to migrate towards the surface of particles. Vibro-milled powders show a better sinterability in comparison to jet-milled powders. Pulverization produces little effect on the properties of precursor fused periclase.