The relative complex dielectric function epsiv*(omega)=epsiv' - jepsiv" of pulverized samples of different grade limestone (cement grade, chemical grade, steel melting soap (SMS) grade and dolomite), coal (lignite) and limestone-coal mixtures (65 wt% + 35 wt%) were measured at 10.1 GHz over a range of bulk densities from loosely to tightly packed. It is found that for these powdered samples, the (e')1/3 values with a range of varying densities are governed by the linear relationship and also depends on their chemical composition. The e' values of pulverized and solid samples were estimated using various dielectric equations of heterogeneous mixtures.