The Earth's mantle is primarily made up of the following elements by percentage composition:
- Oxygen: approximately 44.8%
- Magnesium: about 22.8%
- Silicon: around 21.5%
In addition to these main elements, the mantle also contains smaller amounts of iron, aluminum, calcium, sodium, and potassium. These elements exist mostly in the form of silicate minerals, which are oxides combining these elements with oxygen. The most common compounds in the mantle include silicon dioxide (SiO2) and magnesium oxide (MgO). The mantle's composition is dominated by silicate rocks such as peridotite, which is rich in magnesium and contains minerals like olivine, pyroxenes, spinel, and garnet. The mantle is denser than Earth's crust but less dense than the core, which is mainly iron and nickel.
