For radiocarbon dating to be possible, the material must once have been part of a living organism. This means that things like stone, metal and pottery cannot usually be directly dated by this means unless there is some organic material embedded or left as a residue.

Can you carbon date rock?

Geologists do not use carbon-based radiometric dating to determine the age of rocks. Carbon dating only works for objects that are younger than about 50,000 years, and most rocks of interest are older than that. Over time, carbon-14 decays radioactively and turns into nitrogen.

Is carbon-14 a radioactive isotope?

It is nearly 80 years since the discovery of carbon-14, a radioactive isotope of the sixth element. Living organisms constantly take up 14C, and after they die, the isotope decays at a known rate. By measuring the amount left in a carbon-based sample, it is possible to calculate its age.