The spinning nickel-iron core of the earth is just a shell around the even heavier metals of the inner core. That’s where all the lead, uranium, platinum, gold silver etc. is................
The inner core is mostly solid nickel and iron at 5,200°C (solid due to the extreme pressure). But at the center of that is it likely all the heavy elements such as gold and uranium likely settled before the crust solidified. It is conjectured that there is even U-235 fission still occurring, making it into a nuclear reactor. We are still learning things about the earth’s inner structure.