Just to muddy the water, some iron in the earth core is thought to have come here from a massive collision in the early solar system between the earth and a minor planet.
http://www.youtube.com/watch?v=HAx22sEOU5A
http://www.youtube.com/watch?v=HAx22sEOU5A
You can fix ignorance, you can't fix stupid.
Tinkety Tonk and down with the Nazis.