Silicate
Definition
The largest group of minerals, characterized by silicon-oxygen tetrahedra (SiO₄) as their basic structural unit. Silicates make up about 90% of Earth's crust.
Example
Quartz, feldspar, and mica are all silicate minerals.
The Building Blocks of Earth
Silicates are the most abundant group of minerals on Earth, making up over 90% of the Earth's crust. They are all based on the same fundamental chemical unit: the silicon-oxygen tetrahedron (SiO₄). This consists of one silicon atom surrounded by four oxygen atoms in a pyramid shape. How these pyramids link together defines the type of silicate.
Classification of Silicates
- Nesosilicates (Isolated): Tetrahedrons do not touch (e.g., Olivine, Garnet, Topaz).
- Sorosilicates (Pairs): Two tetrahedrons linked (e.g., Epidote).
- Cyclosilicates (Rings): Tetrahedrons form rings (e.g., Beryl/Emerald, Tourmaline).
- Inosilicates (Chains): Single or double chains (e.g., Pyroxenes, Amphiboles).
- Phyllosilicates (Sheets): Sheets of tetrahedrons (e.g., Mica, Talc, Clay).
- Tectosilicates (Framework): 3D network (e.g., Quartz, Feldspar, Zeolites).