Iron meteorites originate from the metallic cores of asteroids that, in their early history, were partially or completely melted due to intense heating and thereby underwent internal separation of their materials. Under the influence of gravity and due to differences in physical and chemical properties, denser iron-nickel metal accumulated in the center, while less dense silicate melts were displaced toward the outer regions, resulting in a layered structure with a metallic core and a silicate mantle. As the core slowly cooled and solidified, characteristic crystal structures formed, and later collisions broke apart these parent bodies, releasing fragments of the core into space that eventually became iron meteorites and can reach Earth.
Iron meteorites can be broadly subdivided into two main genetic groups based on the processes that formed their metallic parent bodies: magmatic and non-magmatic iron meteorites. These two groups are further subdivided into more specific classes based on their chemical and isotopic characteristics. The classification is as follows:
