The determination of some crystallographic parameters of quartz, in the sand dunes of Ouargla, Algeria

• FTIR and XRD confirm that Ouargla sand dunes are mainly consisted quartz.
• Quartz of Ouargla sand dunes crystallizes in α-phase.
• Quartz of Ouargla sand dunes has a highly crystalline nature.
• Quartz of Ouargla sand dunes has a hexagonal system and space group P3221 (154).
• Ouargla sand dunes quartz parameters are: a = b = 4.9294 Å, c = 5.4093 Å, V = 113.832 Å3.

In this work, the crystallographic phase, degree of crystallinity, crystal system, space group and unit cell parameters of quartz in the Ouargla region (Algeria) sand dunes have been determined using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The mid-infrared absorption spectrum showed the characteristic doublet for α-quartz at 796 and 779 cm−1. The observed principle diffractions at the d-spacings of 3.7937, 3.3539 and 1.8204 Å confirm the presence of α-quartz in Ouargla sand. The calculated absorption ratio (degree of crystallinity) of A796/A779≅1.756A796/A779≅1.756 indicated that our quartz exhibits a highly crystalline nature. The crystallographic parameters of quartz in Ouargla sand have been determined through analysis of X-ray diffraction data, carried out using the simulation code DICVOL06. These parameters were found as: hexagonal crystal system, space group P3221 (154), unit cell parameters: a = b = 4.9294 Å, c = 5.4093 Å and V = 113.832 Å3.