Abstract: A process and composition for forming a non-Newtonian oil composition in the form of a grease comprising an overbased calcium salicylate and solid particles of colloidally dispersed calcium carbonate in the form of calcite is disclosed wherein the process comprises the steps of heating overbased calcium salicylate, amorphous calcium carbonate, and a converting agent comprising a fatty acid of twelve to twenty-four carbon atoms in an oleaginous medium, and then adding sufficient water, alcohol, and carbon dioxide to the mixture to complete the conversion of the amorphous calcium carbonate to calcite.