Tectosilicates

This subclass is also known as the framework silicates because its structure is characterized by a very strong and stable three-dimensional framework. Nearly 75% of the Earth's crust is made up of minerals of the tectosilicate class. This is because the aluminum ion can easily substitute for the silicon ion creating a -5 charge in the crystal. Since the charge must be balanced, additional cations are needed, creating the numerous minerals.

Minerals

Albite
Anorthite
Chabazite
Danburite
Heulandite
Leucite
Microcline
Natrolite
Nepheline
Opal
Orthoclase
Quartz
Sodalite
Stilbite

Mineral Photos courtesy of R.Weller/Cochise College