A process for manufacturing a thermally and/or electrically conducting solid, in which: at least one doped aqueous dispersion is prepared, the dispersion including a mica powder and at least one dopant powder, these being dispersed in a non-ionic aqueous liquid, each dopant being chosen from graphites, with the exception of unexpanded expandable graphites, the mica representing at least 5% by weight of the solid matter of the dispersion, the dopant(s) representing 1 to 95% by weight of the solid matter of the dispersion and a proportion of each dopant being chosen depending on the desired thermal and electrical conductivities; each doped aqueous dispersion undergoes a forming operation, the proportion by weight of solid matter in the dispersion having been chosen so as to obtain, in the case of the doped aqueous dispersion, a viscosity compatible with the forming technique used; and the doped aqueous dispersion is left to undergo form consolidation, by at least the evaporation of the aqueous phase of the dispersion liquid.