Iron is a ubiquitous element with a rich (i.e., complex) chemical behavior. It possesses three oxidation states, metallic iron (Fe0), ferrous iron (Fe2+) and ferric iron (Fe3+). The distribution of these oxidation states is markedly stratified in the Earth.

Planetary objects other than Earth show similar stratification, including Mars, which has a metallic iron-rich core, a ferrous iron-rich mantle, and a ferric iron-rich surface, giving Mars its red color through the presence of nano-crystalline hematite. Many questions pertaining to the establishment and implications of such stratification remain unanswered, such as what were the P...

First Page Preview

First page PDF preview
You do not currently have access to this article.