High emissivity coatings are widely used in many cases where heat transfers through electromagnetic radiation that arises due to the temperature of a body. Extensive theoretical and experimental efforts have been made to synthesize and investigate high emissivity coatings. The emissivity can be improved through various or combined mechanisms. The emissivity here is characterized to describe the surface radiative property which involves the transfer of heat by electromagnetic radiation arising due to the temperature of a body. the surface emissivity, which is the efficiency of the surface for transmitting the radiant energy generated in the surface into its surroundings. The latter depends on the temperature (but the relationship between emissivity and temperature is not definite, depending on material nature, surface parameters and wavelength), composition, surface roughness, coating thickness, wavelength, and physical parameters of the surface. The characterization of emissivity is still a topical problem. For this purpose, silica-based glasses powders with different concentrations of Fe₂O₃ have been prepared, pressed, melted, crushed then deposited as a coating on ceramic tiles, in order to characterize their emissivity, reflectance spectra were measured from 0.8-2.5 µm, from the latter we could extract the emissivity spectra at room temperature for the same spectral range. X-ray diffraction analysis were measured to examine the effect of the iron oxide concentration on the crystallization phase of the glass matrix. To study and determinate, the surface morphology, microstructure, glass coating thickness and coating adhesion with the ceramic, micrographs was taken using and Scanning Electronic Microscope (SEM). Reflectance (Emissivity) spectra showed that the higher the Fe₂O₃ concentration the lower the reflectance goes the higher goes the emissivity in the IR spectra, where the XRD patterns showed that the crystallization phases (peaks) appears from a high concentration of Fe₂O₃ concentration. Finally, the SEM images showed that layer thickness varies in the same sample surface and from a sample to another, and a quite good adherence between glass coating and ceramic support.