Silicates are the most common mineral group on Earth, and they are made up of silicon and oxygen. These two elements combine to form a tetrahedral structure (SiO4) which then links together in various ways to create different types of silicates.

Here are some examples of common silicate minerals:

* Quartz: (SiO2)

* Feldspar: (various combinations of aluminum, silicon, oxygen, sodium, potassium, and calcium)

* Mica: (various combinations of aluminum, silicon, oxygen, potassium, and magnesium)

* Olivine: (Mg2SiO4 and Fe2SiO4)

These minerals are found in a wide variety of rocks, from igneous and metamorphic rocks to sedimentary rocks. They are essential components of the Earth's crust and mantle.