A process is disclosed for extracting diamondoid compounds from a hydrocarbon gas stream. The process includes two stages, each of which alone is effective to remove diamondoids from a hydrocarbon gas stream. The first stage comprises contacting the diamondoid-laden hydrocarbon gas with a suitable solvent to preferentially dissolve the diamondoids into the solvent. Diesel fuel is the preferred solvent for this first stage. The second stage comprises sorbing diamondoids from the diamonoid-laden hydrocarbon gas with silica gel. The most preferred embodiment of the invention is a serial process in which a diamondoid-laden gas is first treated in the solvation stage and the partially purified gas is further resolved in the silica gel sorption stage. The invention still further includes a process for segregating adamantane and diamantane when both are separated from a hydrocarbon gas stream.