The characterization of Indian standard sand (IS650:1991 as per B.I.S. approval) was performed by X-ray diffraction, IR and Raman spectroscopy, and nuclear magnetic resonance techniques. The principal reflections occurring at the d-spacings of 4.2408, 3.3440, and 1.8292 A° confirm the presence of α-quartz crystalline structure in the sample. The calculated unit cell parameters are: a = 4.9294 A°, c = 5.4093 A°, and V = 113.832 A°3. Mid-IR spectrum shows the characteristic doublet for α-quartz at 797 and 778 cm -1 . The Al/Al+Si ratio has been calculated from the position of the absorption band at 1100 cm -1 . Raman spectrum of the sample has two strong peaks at 203 cm -1 and at 462 cm -1 for A1 vibrational mode characteristic of α-quartz. Two bands at 1410 and 1930 nm in near-IR spectrum indicate the presence of both molecular water and an OH group. A broad double band centered near 1210 nm and a weak band at 1050 nm attest the presence of Fe 2+ and Fe 3+ respectively in the sample. The signal near g ~ 4 is characteristic of isolated Fe 3+ ions in the distorted octahedral or tetrahedral crystalline field. 29 Si NMR spectrum shows a strong signal at -107 ppm corresponding to quartz.Keywords: sand, X-ray diffraction, infrared and Raman spectra, 29 Si nuclear magnetic resonance spectroscopic techniques.Introduction. Silica forms a basic mineral for all types of rocks. Silica exists in many different polymorphs: α-and β-quartz, α-and β-cristobalite, coesite, and stishovite. The most stable phase of silica at ambient conditions is α-quartz. Quartz is one of the most abundant minerals found in the Earth crust (12% of its weight). It was formed under a wide range of P-T conditions prevailing in the crust. In different crustal environments, quartz is crystallized from silicate melt, precipitated from aqueous solution, or formed as a result of solid state transformation during metamorphic events. This mineral belongs to the tectosilicate class and the structure is built from SiO 4 tetrahedra which are linked by sharing each of their corners with another tetrahedron. In the three-dimensional framework thus formed every silicon has four oxygens and every oxygen has two silicons as nearest neighbors [1]. The unit cell of the crystal structure consists of three SiO 2 groups. The three silicons in the unit cell together with the three other silicons belonging to the adjacent cells form an irregular hexagon possessing only the symmetry of a threefold axis. The impurities commonly found in quartz can be classified as substitutional (occupying the place of Si
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