Silicate Group
The silicate group encompasses around 90% of minerals and it simply means that a mineral has silica within the chemical structure. We made this entry to help explain less common silicates unlike common silicates which have their own pages like quartz, feldspar and garnet.
Silicate minerals are classified into seven major groups according to the structure:
Major group | Structure | Chemical formula | Example |
---|---|---|---|
Nesosilicates | isolated silicon tetrahedra | [SiO4]4− | olivine, garnet, zircon... |
Sorosilicates | double tetrahedra | [Si2O7]6− | epidote |
Cyclosilicates | rings | [SinO3n]2n− | beryl, tourmaline |
Inosilicates | single chain | [SinO3n]2n− | pyroxenes |
Inosilicates | double chain | [Si4nO11n]6n− | amphibole |
Phyllosilicates | sheets | [Si2nO5n]2n− | micas and clays |
Tectosilicates | 3D framework | [AlxSiyO(2x+2y)]x− | quartz, feldspars, zeolites |