Final answer:
The silicates are the most abundant minerals in the Earth's crust and mantle, making up approximately 90% of the crust. These minerals are based on the silicon-oxygen tetrahedron, with oxygen and silicon being the most abundant elements in these Earth layers. Quartz is a typical example of a silicate mineral.
Step-by-step explanation:
The most abundant class of minerals in the Earth's crust and mantle are the silicates. These minerals constitute approximately 90% of the Earth's crust, and their structures are based around the silicon-oxygen tetrahedron, SiO4. Silicates are the main component of the crust and mantle due to the high abundance of oxygen and silicon in these layers. Minerals such as quartz are widespread examples of silicate minerals.
Furthermore, the crust is predominantly composed of silicon oxides and aluminum oxides. The distribution of minerals shows that silicates vastly outnumber other mineral classes, such as carbonates, sulfides, and oxides. Elements such as lithium, sodium, and potassium are commonly found in silicate or phosphate minerals, while aluminum is abundant in clay and bauxite, an impure aluminum oxide hydroxide.
The fundamental role of silicates in the Earth's composition is evident not only in the continental crust but also in the oceanic crust, which varies in thickness. The overall chemical composition of planets like Earth, with their oxidized chemistry, indicates that silicate minerals form a significant part of their mass.