Hydrated silica (original) (raw)

Hydrated silica is a form of silicon dioxide, which has a variable amount of water in the formula. When dissolved in water it is usually known as silicic acid. It is found in nature, as opal (which has been mined as a gemstone for centuries), and in the cell walls of diatoms. It is also manufactured for use in toothpaste. Hydrated silica can be dehydrated to produce silica gel, which is used as a desiccant. It is also used in various paints and varnishes and in the production of beer.