The present invention relates to hydronium stabilized silicic acid nanoparticles able to dissolve in aqueous environments, to their preparation and use. The present invention provides a stable suspension of colloidal silicic acid nanoparticles having a pH lower than 0.9, a molar silicon concentration between 0.035 and 0.65, a free water concentration of at least 30% (w/v) and a ratio between hydronium ion and Si molar concentrations higher than 2 and preferably inferior to 4. The present invention further provides a method for preparing a stable suspension of colloidal silicic acid nanoparticles, which comprises the steps of providing an aqueous inorganic or organic silicon solution and quick mixing said aqueous inorganic or organic silicon solution with water containing a strong acidic compound at a temperature inferior at 30°C, preferably comprised between 1 and 25°C, to form a suspension of colloidal silicic acid nanoparticles having a pH lower than 0.9, stabilized by hydronium ions, the ratio between hydronium ions and Si molar concentrations being higher than 2 and preferably inferior to 4, for a molar silicon concentration between 0.035 and 0.65 and a free water concentration of at least 30% (w/v).