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An exhaustive structural analysis was carried out on three Indian coals (ranging from sub-bituminous to high volatile bituminous coal) using a range of advanced characterization tools.Detailed investigations were carried out using UV-Visible spectroscopy,X-ray diffraction,scanning electron microscopy coupled energy dispersive spectroscopy,Raman spectroscopy and Fourier transform infrared spectroscopy.The X-ray and Raman peaks were deconvoluted and analyzed in details.Coal crystallites possess turbostratic structure,whose crystallite diameter and height increase with rank.The H/C ratio plotted against aromaticity exhibited a decreasing trend,confirming the graphitization of coal upon leaching.It is also found that,with the increase of coal rank,the dependency of I20/I26 on La is saturated,due to the increase in average size of sp2 nanoclusters.In Raman spectra,the observed G peak (1585 cm-1) and the D2 band arises from graphitic lattices.In IR spectrum,two distinct peaks at 2850 and 2920 cm-1 are attributed to the symmetric and asymmetric-CH2 stretching vibrations.The intense peak at ～ 1620 cm-1,is either attributed to the aromatic ring stretching of C=C nucleus.