The Earth's interior consists of rock and metal. It is made up of four main layers: <span>1) the inner core: a solid metal core made up of nickel and iron (2440 km diameter) </span> <span>2) the outer core: a liquid molten core of nickel and iron </span> <span>3) the mantle: dense and mostly solid silicate rock </span> <span>4) the crust: thin silicate rock material</span>
