Abstract: The present invention concerns mixtures containing at least one luminescent composition, luminescent compositions, processes for the production of luminescent compositions and uses of the mixtures and compositions. To provide mixtures which can be used in small amounts for marking articles, substances and materials, wherein analysis and copying thereof is made more difficult, it is proposed according to the invention that the mixtures include at least one luminescent composition and at least one substantially non-luminescent composition, wherein the luminescent composition includes a mixed crystal of inorganic salts and the at least one substantially non-luminescent substance is an inorganic salt or a mixed crystal of inorganic salts.