The inner core is the dense center of Earth. is in the range 5000–6000 K and inner core pressures are ∼330–360 GPa. It is believed that the core also contains a large amount of gold and platinum, so much that if it was poured onto the surface it would cover the entire planet up to 1 1/2 feet. Knowledge of the exact composition and structure of the Earth's inner core would enable a better understanding of the internal structure and dynamics of the Earth as a whole; in … some (4-5%) nickel and the remainder oxygen, silicon, hydrogen and. This is hardly surprising given that the temperature of the Earth's core ( q.v.) Earth's core has two parts, a solid iron inner core and a molten outer core, which is composed of a nickel-iron alloy. The Earth's core is thought to be predominantly iron (85 %) with. The outer core begins about 1,800 miles under the crust. The solid inner core is complex and not yet fully understood. The inner core, which is about 750 miles thick, is made primarily of iron. Theories on the formation of Earth suggest that the inner core is composed of iron and nickel heated up to a temperature of around 9,800 degrees F. Unlike the outer core, the inner core is mostly solid. Although the iron in the inner core is even hotter (10,000º F or more — as hot as the surface of the Sun!) than the outer core, the intense pressure from the rest of the planet is so great that the iron cannot melt. The Inner Core is a solid ball composed of an element named NiFe. Ni for Nickel and Fe for Ferrum also known as Iron.