Amorphous Se was converted into fibrous crystals of hexagonal Se or polyhedral crystals of alpha-monoclinic Se when exposed to organic fluids at room temperature for several days. The growth phase was dependent upon the dielectric constant of the organic liquids. It is notable that hexagonal Se and alpha-monoclinic Se formed under vapors of d- and l-camphor, respectively. It is proposed that the organic compounds do not act as solvents, but play a catalytic role in the reactions.