What does the earth's inner cores look like?
Earth's inner core is a solid ball of mostly iron and nickel, with a few lighter elements.
The nickel-iron alloy found in the core is known as NiFe. It is not the only constituent of the core, however, since under core pressure, pure NiFe is denser than the core, which indicates there are lighter elements present, such as oxygen, carbon or silicon.
Even though it is the hottest part of the Earth, it is still solid, because there are 6000 miles of rocks and metals weighing down on it, compressing it until it loses any of its fluidity.
It is roughly spherical because the immense force of weight is almost equal in all directions, and so it would naturally form a spheroid shape.
The inner core is about