The Earth is almost a sphere. These are its main layers, starting with the outermost:

• crust – relatively thin and rocky
• mantle – has the properties of a solid, but can flow very slowly
• outer core – made from liquid nickel and iron
• inner core – made from solid nickel and iron

The Earth’s lithosphere is the rigid outer layer that is made up of the crust and the part of the mantle just below it. The lithosphere is made up of a mixture of minerals.