silica gel is a highly porous, noncrystalline form of silica that is used for a variety of things, including to remove moisture from gases and liquids, thicken liquids, give paints and synthetic films a dull surface, and so on. Silica gel is a form of silicon dioxide (silica) that is amorphous and porous. It is made up of a triangular framework of alternating silicon and oxygen atoms that is irregular and has nanometer-scale voids and pores.