Mineralogical and geochemical peculiarities of oxide-ferriginuous sediments of the Alexandrinka massive sulfide bearing area (Southern Urals) are reviewed and criteria for prognosis of massive sulfide ores are established. They allow to distinct the ore-controlling oxide-ferriginuous products of submarine oxidation of sulfide sediments (gossanites) from the barren apohyaloclastite halmyrolitites (jasperites). Enriched in Ti chlorite-smectites, the increased apatite concentations and also the high Cu, Zn, Pb, Те, Bi, Au, and REE contents correlating with Ba, Nb, Hf, Та, Cs and Sr are the main indicators for gossanites.