Here's a breakdown of its composition:

* Crust: The outermost layer, composed of relatively light elements like oxygen, silicon, aluminum, iron, calcium, sodium, potassium, and magnesium.

* Mantle: The thickest layer, primarily composed of silicate minerals rich in iron and magnesium.

* Core: The Earth's center, composed of a solid inner core primarily made of iron with a nickel-iron liquid outer core.

While rock is the main component, the Earth also contains:

* Water: About 71% of the Earth's surface is covered in water, making it a significant component.

* Atmosphere: A layer of gases surrounding the Earth, primarily nitrogen and oxygen.

* Trace elements: Various other elements found in small amounts throughout the Earth.

So, while rock is the dominant material, the Earth is a complex and diverse planet with various other important components.