The basic structural unit of silicates is SiO4-4.
Silicates are the minerals containing silicon and oxygen in tetrahedral SiO 4 4- units, which are linked together in several patterns. Depending on the way the tetrahedral units are linked, the silicates are classified into the following types.
- Ortho silicates (or Nesosilicates)
- Pyro silicate (or Sorosilicates)
- Cyclic silicates (or Ring silicates)
- Chain silicates (or pyroxenes)
- Double chain silicate (or amphiboles)
- Sheet or phyllosilicates
- Three dimensional (or tecto) silicates
Silicate minerals are prevalent in the Earth crust since Oxygen and Silicon are the most abundant elements. The basic silicate minerals readily react with weak acids and undergo weathering. Silicate minerals are the most common of Earth’s minerals and include quartz, feldspar, mica, amphibole, pyroxene, and olivine.