Silicates are a family of polyatomic anions consisting of silicon and oxygen, usually with the general formula . They are the most abundant minerals on Earth, making up approximately 90% of the Earths crust/Descriptive_Chemistry/Elements_Organized_by_Block/2_p-Block_Elements/Group_14%3A_The_Carbon_Family/Z014_Chemistry_of_Silicon_(Z14)/Silicates). Silicates are encountered as silicate minerals, which are rock-forming minerals made up of silicate groups. The basic structural unit of all silicate minerals is the silicon tetrahedron in which one silicon atom is surrounded by and bonded to four oxygen atoms, each at the corner of a regular tetrahedron. The oxygen atoms link to other cations (Mn+), and this Si-O-M-O-Si linkage is strong and rigid, which properties are manifested in the rock-like silicates. Silicates can be classified according to the length and crosslinking of the silicate anions, and some of the subcategories of silicates are:

• Nesosilicates: made up of units of independent tetrahedrals. Some of the minerals that contain nesosilicates are olivine, garnet, zircon, kyanite, topaz, and staurolite/Descriptive_Chemistry/Elements_Organized_by_Block/2_p-Block_Elements/Group_14%3A_The_Carbon_Family/Z014_Chemistry_of_Silicon_(Z14)/Silicates).
• Sorosilicates: consisting of double tetrahedral groups in which one oxygen atom is shared by two tetrahedrons.
• Cyclosilicates: arranged in rings made up of three, four, or six tetrahedral units.
• Inosilicates: showing a single-chain structure wherein each tetrahedron shares two oxygen atoms.
• Phyllosilicates: consisting of sheets of linked tetrahedra.
• Tectosilicates: consisting of a continuous framework of tetrahedra, each sharing all four oxygen atoms.

Silicates are versatile materials, both natural (such as granite, gravel, and garnet) and artificial (such as Portland cement, ceramics, glass, and waterglass), and are extremely important because the cement, ceramic, and glass industries are based on their chemical composition.