Radiocarbon helps date ancient objects—but its not perfect. For nearly 70 years, archaeologists have been measuring carbon-14 levels to date sites and artifacts. Nothing good can last—and in the case of carbon-14, a radioactive isotope found in Earths atmosphere, thats great news for archaeologists.

What items can be dated with carbon-14?

Samples that have been radiocarbon dated since the inception of the method include charcoal, wood, twigs, seeds, bones, shells, leather, peat, lake mud, soil, hair, pottery, pollen, wall paintings, corals, blood residues, fabrics, paper or parchment, resins, and water, among others.