What are meteorites composed primarily of iron and nickel called?

Meteorites that are composed primarily of iron and nickel are referred to as siderites. These are a specific type of meteorite known for their metallic composition, which distinguishes them from other types of meteorites. Siderites are typically associated with the core materials of differentiated bodies, such as larger asteroids, which allows them to undergo differentiation into layers that can include metallic cores.

Conversely, stony meteorites consist mainly of silicate minerals and do not have the significant metallic composition that defines siderites. Chondrites, another classification of stony meteorites, contain small mineral clasts or chondrules and are also not primarily composed of iron and nickel. Meteor showers, meanwhile, refer to the phenomenon of meteoroids entering Earth's atmosphere and burning up, creating a visual display, and do not classify any meteorite type.

Understanding the characteristics of siderites helps in identifying their origins and the conditions under which they formed, highlighting their importance in the study of planetary formation and the history of the solar system.