This study reports the chemical composition of seven sandstones (OH1-OH7) from Ouargla desert in south-east of Algeria, then the investigation of these samples to be used as precursor for the hydrothermal synthetesis of piezoelectric mater in thin films form. Fourier-transform infrared (FT-IR) spectra shows the characteristic vibration bond peaks for the seven samples documenting the presence of quartz and calcite. Moreover, chemical composition of Ouargla sandstones has been determined by energy dispersive X-ray (EDS) and X-ray diffraction (XRD) allowed mainly a composition avrage major of 86.86 % α-quartz (SiO2) and minor of 13.14 % calcite (CaCO3). The EDS analysis revealed the presence of solid solution in the crystal lattice of six samples of the sandstones with trace amounts of Fe, Al, Ag, Na, K. The aqua regia digestion method was used to extract silicon and calcium from the rock samples in to synthesis the thin films. From (FT-IR), (SEM-EDS) and (XRD) we show that synthesis thin films at different temperture are composed mainly of 90.66 % calcite (CaCO3)/9.33 % α-quartz (SiO2) and 69 % α-quartz (SiO2)/31% Sodium Chloride (NaCl). The crystallite sizes of the sandstones were calculated and estimated to be nanometric, in contrast the thin films are not nanometric.