Here's why:

* Abundance: Silicates make up about 90% of the Earth's crust. They are the building blocks of most rocks, from granite to sandstone.

* Diversity: There are many different types of silicates, with a wide range of properties. This allows them to form a diverse array of rocks.

* Key role in Earth's processes: Silicates play a crucial role in many Earth processes, such as weathering, erosion, and the formation of soil. They also play a role in the formation of minerals, rocks, and even the Earth's atmosphere.

Examples of common silicate minerals:

* Quartz: Used in glassmaking, electronics, and other industries.

* Feldspar: A common mineral found in granite and other igneous rocks.

* Mica: Used in insulation, paint, and other products.

* Clay minerals: Important components of soil and used in ceramics.

While other classes of minerals like carbonates, oxides, and sulfides are also important, silicates' sheer abundance and impact on Earth's processes make them the most significant class of rock-forming minerals.