Bones into Iron fossils: These fossils are formed when the bones are replaced by Iron pyrite or other Iron ores; it forms bones-shaped Iron. This process is called Pyritization, The mineral iron pyrite is an iron sulfide with the formula FeS2. So it is clear that bones are preserved for millions of years when it is replaced by minerals like calcite and silica forming a IRON model. Visit Profile For more miracles of Quran | Halal Research