A process for recovering diamondoid compounds from a fluid mixture thereof with other hydrocarbonaceous compounds which comprises contacting said mixture with a porous solid, for example, a zeolite, having pore opening large enough to admit said diamondoid compounds thereinto and small enough so that at least 50% of the external atoms of said diamondoid compounds are capable of simultaneously contacting the internal walls of the pores of said solid under conditions conducive to absorption of diamondoid compounds by said solid; and then desorbing the absorbate comprising diamondoid compounds from said solid absorbant.