Silicate
A silicate is any member of a family of polyatomic anions consisting of silicon and oxygen, usually with the general formula [SiO(4−2x)−4−x]n, where 0 ≤ x < 2. The family includes orthosilicate SiO4−4 (x = 0), metasilicate SiO2−3 (x = 1), and pyrosilicate Si2O6−7 (x = 0.5, n = 2).