What Is Potassium-40 Used To Date?

The potassium-argon dating method is a technique for establishing the age of rocks by calculating the proportion of radioactive argon to radioactive potassium that is present in the sample of rock being dated. In minerals and rocks, radioactive potassium-40 eventually decays into radioactive argon-40, and potassium-40 also decays into calcium-40. This technique of dating relies on this process of radioactive decay.