Abstract: Novel powders, and resinous compositions bearing said powders, characterized by excellent chemical stability, electrical conductivity, and energy-absorbing characteristics. These three characteristics can be utilized, alone or combination, in forming many novel articles including microwave shielding apparatus, magnetic recording media, explosives, and the like. The more advantageous powders are characterized by a very thin coating of an electrically conductive metal carbide, metal silicide, or metal boride upon the surface thereof, and a metal core.