The elements calcium, magnesium, aluminum, silicon and potassium are part of oil shales, precisely they are found in the mineral matrix. In this work, hydrotreating in a dynamic regime (21°C/min) and under standard hydrogen pressure (1atm) was carried out and these elements were followed quantitatively before and after reaction by the dispersive X-ray diffraction technique (RXD). The compounds formed are hydrides which are mainly fuels, indeed, calcite, an element of oil shale, under hydrogen produces hydrolith (CaH2), dolomite under hydrogen produces magnesium hydride (MgH2), similarly kaolinite produces monosilane (SiH4) also carbon under hydrogen produces methane. It should be noted that oil shale around the world vary in their oil production capacity and quality. For example, the Green River shale in the western United States contains a high concentration of hydrogen relative to organic carbon and yields a high yield by simple decomposition using a conventional inert gas. However, much other shale that resembles to the Devonian shale in the eastern United States contains a lower concentration of hydrogen than the Green River (J.C. Janka: 1984).