Different grades of stoichiometric and non-stoichiometric dense magnesium aluminate spinel (MgAl 2 O 4 ) grains were prepared by a conventional double-stage firing process using two types of alumina and four types of magnesia raw materials. The MgAl 2 O 4 spinel formation was found to be highly influenced by CaO and moisture present in the precursor oxides as confirmed by thermogravimetry (TG), differential thermal analysis (DTA), and X-ray diffraction (XRD) techniques. The Fourier transform-infrared spectroscopy (FTIR) study of the precursor oxides revealed the presence of moisture. Influence of alumina and magnesia composition on the densification behavior of MgAl 2 O 4 spinels was assessed by characterizing bulk density (BD), apparent porosity (AP), water absorption (WA) capacity, and the microstructures of the stoichiometric, the magnesia-rich, and the alumina-rich spinels sintered at 16501C for 1 h. Sintering studies indicate that to obtain dense stoichiometric spinel grains with 43.35 g/mL BD, o2.0% AP, and o0.5% WA, the spinel powder should possess a median particle size of o2 lm, CaO content of 40.9%, compact (green) density of 41.95 g/ mL, and spinel content of 490%. Among various spinels synthesized, the magnesia-rich spinels exhibited superior properties in terms of high BD, low percentage of AP, and low WA capacity, whereas alumina-rich spinels showed inferior properties. Stoichiometric spinels exhibited an average grain size of 10 lm whereas alumina-rich spinels with 90% alumina had an average grain size of 20 lm. The increase in holding time at higher temperatures enhanced the sintering properties of the spinels, particularly the magnesia-rich spinels. Further, raw mixtures having 40.9% CaO exhibited better sintered properties as compared with others. J ournal