The studies of maksovite of Onega structure dome-deposits were carried out. It is developed on different stratigraphic levels of Zaonega Formation of the Palaeoproterozoic (2.0-1.9 Ga). Maksovite were separated for five groups by content of mineral component, namely, supersilites, normosilites, miosilites, gypersilites and siallites. The geochemical features of maksovites are revealed depend on their stratigraphic position and within dome structures.