Electromagnetic phenomena support the development of exceptional methods for non-destructive, non-contact geomaterial characterization and subsurface process monitoring. Such phenomena include Ohmic conduction, electromagnetic wave propagation and nuclear magnetic resonance. The physical parameters involved include DC conductivity σ, complex permittivity ε*(ω) and complex permeability μ*(ω) spectra, and nuclear magnetic resonance relaxation. These parameters reflect mineralogy, particle and pore size distributions, pore network topology and anisotropy, fluid composition, state and fluid-mineral interaction. Proper data interpretation requires careful understanding of underlying physical concepts and measurement methods.