KÖSTROSOL® is a milky mobile aqueous dispersion of amorphous silicon dioxide nanoparticles. This large-size colloidal silica has a negatively charged surface (anionic) which is stabilized by Alkaline (Na). The particles are made from high-purity alkali silicate. They are spherical and generally non-crosslinked and are hydroxylated at the surface. KÖSTROSOL® colloidal silica is commonly used to polish glass, optical lenses, bearings, sapphire, and single crystals such as fluorspar.