Silicates in which all the oxygen atoms of [SiO4]4- tetrahedra are shared with other tetrahedra to form a three-dimensional network are called three dimensional or tecto silicates. They have general formula (SiO2)n.
eg: Quartz These tecto silicates can be converted into Three-dimensional aluminosilicates by replacing [SiO4]4- units by [AlO4]5- units. E.g. Feldspar, Zeolites etc.,
