  Shungite quantum dots are associated with nanosize fragments of reduced
graphene oxide similarly to synthetic graphene quantum dots thus forming a
common class of GQDs. Colloidal dispersions of powdered shungite in water,
carbon tetrachloride, and toluene form the ground for the GQD photonic
peculiarities manifestation. Morphological study shows a steady trend of GQDs
to form fractals and a drastic change in the colloids fractal structure caused
by solvent was reliably established. Spectral study reveals a dual character of
emitting centers: individual GQDs are responsible for the spectra position
while fractal structure of GQD colloids provides high broadening of the spectra
due to structural inhomogeneity of the colloidal dispersions and a peculiar
dependence on excitation wavelength. For the first time, photoluminescence
spectra of individual GQDs were observed in frozen toluene dispersions which
pave the way for a theoretical treatment of GQD photonics.
