Preparation and Microstructure of Bluish Glass

Bluish glass was successfully prepared by mixing oxides and carbon as a reductant into the starting materials, whereas the addition of only α-Fe2O3 into the glass raw materials provided greenish glass. The chemical state of the iron ions in the glass was likely modified from Fe3+ to Fe2+ by the reducing atmosphere caused by carbon during the heating process. Mössbauer spectra and spectrophotometric measurements indicated that the bluish glass contained a high proportion of Fe2+ (67.4%) and mainly absorbed visible light with wavelengths longer than 500 nm.