To establish the age of a rock or a fossil, researchers use some type of clock to determine the date it was formed. Geologists commonly use radiometric dating methods, based on the natural radioactive decay of certain elements such as potassium and carbon, as reliable clocks to date ancient events.

How does radiometric dating of rocks work?

Radiometric dating, often called radioactive dating, is a technique used to determine the age of materials such as rocks. It is based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates.

How do you tell if a rock has a geode inside?

Tell-Tale Signs of a GeodeGeodes are usually spherical, but they always have a bumpy surface.Geodes will sometimes have loose material inside, which can be heard when shaking the rock. Geodes are usually lighter than their size would indicate since the interior doesnt contain any material.More items