Silicates

Silicates

A large number of silicates minerals exist in nature. Some of the examples are feldspar, zeolites, mica and asbestos. The basis structural unit of silicates is SiO44- in which silicon atom is bonded to four oxygen atoms in tetrahedron fashion, in silicates either the discrete unit is present or a number of such units are joined together via corners by sharing 1,2,3 or 4 oxygen atoms per silicate units. When silicate units are linked together, they form chain, ring, sheet or three-dimensional structures. Negative charge on silicate structure is neutralized by positively charged metal ions. If all the four corners are shared with other tetrahedral units, three-dimensional network is formed.
 Two important man-made silicates are glass and cement.
Silicates



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