An emulsion of water and oil comprising a solution of silicic acid and one or more stabilizing compounds in water, and one or more block copolymers as emulsifiers. Aside from water-in-oil and oil-in-water emulsions, the invention also offers co-emulsions of water with silicic acid in oil in water, water in oil in silicic acid with water, and oil in water with silicic acid in oil. Aside from silicic acid, the emulsion or co-emulsion preferably comprises one or more other, oil-soluble and/or water-soluble, active ingredients.The stable emulsions with silicic acid according to the invention can be favorably used for medical or cosmetic purposes, as dietary supplements, liquid fertilizers, crop protection agents, biocides, biostimulants, plant nutrients, soil improvers, catalyzers, antioxidants, or household products.