Silicate

A silicate (SiO₄4-) is a compound containing a silicon bearing anion. The great majority of silicates are oxides, but hexafluorosilicate (2−) and other anions are also included. This article focuses mainly on the Si-O anions. Silicates comprise the majority of the earth's crust, as well as the other terrestrial planets, rocky moons, and asteroids. Sand, Portland cement, and thousands of minerals are examples of silicates.