The procedure is developed for modification of diamond surface by luminophore-containing organic compositions. The compositions are composed of an organic luminophore—scintillation anthracene, inorganic luminophore K-35 and cetane. Indication compositions are synthesized based on the selected luminophores and organic liquids and tested using pilot separator POLYUS-M. Spectral-kinetic characteristic of luminophopre-containing organic-mineral compositions, treated weakly luminous diamond crystals and kimberlite minerals are determined. The compositions ensuring better spectral-kinetic characteristics and higher extraction of diamonds during H-ray luminescence separation are selected.