The effectiveness of enhanced oil recovery techniques depends strongly on the stability of the crude oil emulsions. The ionic nature of the aqueous phase influences emulsion stability and can vary between oil wells. To better understand the influence specific ion effects may have on these systems, the stability was measured using the bottle test for crude oil emulsions in various monovalent and divalent electrolytic solutions. Specific ion effects were not found to have a significant influence on emulsion stability, and restabilization at higher ionic strengths was not observed. Owing to its natural abundance, biocompatibility, and surface modification performance, silica is widely used in industrial applications ranging from surface treatments to medicine and, more recently, to the stabilization of crude oil emulsions. Silica’s effectiveness in these roles is similarly dependent on its colloidal stability characteristics. The aggregation kinetics of bare and sulfonated silica nanoparticles were studied via absorbance measurements. Specific ion effects significantly influenced the colloidal stability of both particles. Restabilization was only observed for the sulfonated silica nanoparticles.