Silicates are the most abundant mineral group, making up over 90% of the Earth's crust. They are composed of silicon and oxygen, along with other elements like aluminum, iron, calcium, magnesium, sodium, potassium, and others.

Here's why silicates are so common:

* Abundance of silicon and oxygen: Silicon and oxygen are the most abundant elements in the Earth's crust.

* Stable and versatile: Silicon and oxygen can bond in various ways, forming a wide range of silicate minerals with different structures and properties.

* Formation from magma: The majority of rocks on Earth are formed from cooling and solidifying magma, which contains high concentrations of silicate minerals.

Examples of common silicate minerals include:

* Quartz: a pure silica mineral (SiO2)

* Feldspar: a group of minerals containing aluminum, silicon, and oxygen, along with other elements

* Mica: a group of sheet silicate minerals

* Pyroxene: a group of chain silicate minerals

* Amphibole: a group of double chain silicate minerals

While silicates are dominant, other minerals also play important roles in rocks. Some examples include:

* Carbonates: like calcite (CaCO3) in limestone

* Oxides: like hematite (Fe2O3) in iron ores

* Sulfides: like pyrite (FeS2) in some ore deposits

However, silicates are the foundation of most rocks on Earth.