Black shales (BS) accumulate economic and biologically important trace metals such as Re, precious metals, U, V, Mo, Cu, Ni and Co above expected Clarke concentrations. We extracted colloid-salt fraction with particle size <1000 nm from BS with water under special conditions. In nano-fraction the detection limit for rare and trace elements are lower by 2-3 orders of magnitude, show maximum content for Re-22, 6 mg/l; Ag-9, 7 mg/l; Au-1, 4 mg/l; Pd-1, 7 mg/l; and Pt-0,5. Our data reveals a BS nanogeochemistry that could enhance geochemical ore prospecting methods and open new ways for extracting low concentration elements from BS.