Upper Cretaceous Duwi Formation oil shale deposits in phosphate mines at Safaga – Quseir area, Red Sea, Egypt are known to have source rock potential. For this reason, the inorganic geochemical characteristics of black oil shale samples were investigated mineralogically using the X-Ray Diffraction (XRD) technique which indicates that, minerals of this shale are consisting predominantly of quartz, calcite, dolomite, gypsum, hematite and pyrite in addition to apatite and Fluor apatite. While the clay minerals consisting predominantly of smectite mixed layer in addition to kaolinite with different percentages. The studied shales investigated by Flame atomic absorption instrument for their chemical composition. It shows many trace elements enrichment distribution affected by weathering. The studied shale’s exhibit high concentration of Co, Cr, Cu, Ni, V and Zn due to oxidation, weathering and subsequent mobilization of the organic matter.