The original results of the high_precision mineralogical and geochemical study of the Archean auriferous mineralization of the Koikary structure, confined to the Koikary-Vygozero regional shear zone, are reported. The metasomatic rocks (beresites and chloritic propylites with margarite) and ore assemblages of the Koikary Quarry occurrence, which comprise over 60 minerals, such as sulphides, sulphoarsenides, bismuthotellurides, Pb-Sb-sulphosalts and native metals, are described. Noble-metal mineralization is represented by native gold, electrum, kustelite, argentopentlandite, owyheeite, hessite, stuetzite, acanthite, matildite, tetrahedite and Ag-galena. The conditions of formation of the noble_metal mineralization were determined, the mineralization was classified to be of the orogenic mesothermal type with an atypical mineral assemblage, and arguments for that were presented. The Koikary Quarry occurrence was assessed as little promising for gold, based on some criteria. Together with the noble_metal mineralization determined in Koikary pyrite ores (electrum, hessite, acanthite and sulphoarsenides), it is considered a complex positive sign of the gold potential of the Koikary_Vygozero shear zone in general.