Can carbon dating be used on iron?

Iron artefacts are generally dated by association or on stylistic grounds. If the fuel is of a material containing contemporaneous carbon, i.e. has an ambient radiocarbon signature, e.g. charcoal, then we may reliably radiocarbon date the artefact by extracting this carbon.

Can carbon dating be used on humans?

Measuring carbon-14 levels in human tissue could help forensic scientists determine age and year of death in cases involving unidentified human remains. Archaeologists have long used carbon-14 dating (also known as radiocarbon dating) to estimate the age of certain objects.