https://www.sciencenews.org/article/iron-loving-elements-tell-stories-earth’s-history
Eight chemical elements, known as the highly siderophile elements, are preferentially drawn to iron when molten. Most of them have relatively high melting points and resist being corroded or oxidized. Along with the siderophile tungsten, they serve as powerful tracers for how Earth’s interior separated into layers billions of years ago. (In periodic table the eight are Ru Rh Pd W Re Os Ir Pt Au).
For instance, Walker and his colleagues have explored siderophile elements in some of the oldest rocks on Earth. In the Greenland rocks, the rocks contain more of one variety of tungsten, known as tungsten-182, than expected. That isotope forms from the radioactive decay of hafnium-182, which existed only during Earth’s first 50 million years. The Greenland rocks thus serve as a sort of time capsule that helps reveal the history of the early solar system.
Highly siderophile elements can teach about more than just the planet Earth. They can reveal secrets about the history of the moon, Mars and other nearby planetary bodies. That’s because all the worlds in the inner solar system apparently got a dusting of gold, platinum and other highly siderophile elements during meteorite bombardments around 4 billion years ago. This “late accretion” of fresh material could help explain a long-standing puzzle. The amounts of highly siderophile elements in Earth’s mantle are higher than predicted. The moon’s mantle has surprisingly lower amounts of the highly siderophile elements than Earth’s mantle – just about 2 percent as much.