Sodium silicate is a generic name for chemical compounds with the formula Na 2xSi yO 2y+x or (Na 2O) x·(SiO 2) y, such as sodium metasilicate Na 2SiO 3, sodium orthosilicate Na 4SiO 4, and sodium pyrosilicate Na 6Si 2O 7. The anions are often polymeric. These compounds are generally colorless transparent solids or white powders, and soluble in water in various amounts.