In this study, the effects of substituting Al for Fe in 5Na₂O•(Al₂O)_x•(Fe₂O₃)_1-x•8SiO₂ glass, x=0 to 1, and Na₅Al_xFe_1-xSi₄O₁₂(5.1.8) crystal, were investigated using thermal analysis, Fe K-edge X-ray absorption, X-ray diffraction, Raman spectroscopy, and Electron Probe Microanalysis. In both glass and crystallized glass, nearly all the Fe was tetrahedrally coordinated Fe³⁼, as expected from the high concentration of Nasub>2O. The substitution of Al for Fe in the glasses caused the glass transition temperature to increase as polymerization increased, as evidenced by Raman, likely due to both field strength differences of Al vs Fe and a small amount of Fe 2+ network modifier present with Fe. After heat treatment at 700 °C for 24 hours, the glasses had crystallized, forming Na₂SiO₃ and NaAlSiO₄ in compositions with high Al concentrations and the 5.1.8 crystal in compositions with high Fe concentrations. Through electron microprobe, it was determined that <0.04 formula unit Al incorporated into the 5.1.8 crystal, i.e. Na₅Fe_0.96Al_0.04Si₄O₁₂. The 5.1.8 crystal only formed when Fe concentration was higher than Al in the starting glass.