The rare element found in the center of the Earth is believed to be nickel, often found in combination with iron. These two elements constitute a significant part of Earth's core, with nickel being less abundant on the surface but crucial in the core's composition. The extreme pressures and temperatures at the core lead to the formation of an alloy primarily composed of iron and nickel. This layer plays a vital role in generating Earth’s magnetic field through the dynamo effect, crucial for protecting the planet from solar radiation and maintaining a stable environment for life.