The silicates are by far the largest group of minerals. Minerals composed of molecules containing varying amounts of silicon and oxygen are silicates. It is easy to distinguish silicate minerals as a group, although individual minerals are hard to determine.
None are completely opaque, none are fully soluble in acid, and most are light in weight.
Because of the great amount of silicates, they are divided based on their atomic structure. The construction component of all silicates is the tetrahedron , which is one oxygen atom equidimensionally placed around four silicon atoms. These tetrahedrons, when combined with other molecules or tetrahedrons form the silicate minerals. The types of silicates are classified based on the interactive formation of the tetrahedrons. Each group of silicates has a correct ratio of silicon and oxygen, but in some minerals the silicon atoms are replaced by other atoms.