The Potassium-Argon (K-Ar) dating method is the measurement of the accumulation of argon in a mineral. In contrast to a dating method such as C14 dating which measures the disappearance of a substance, K-Ar dating measure the accumulation of argon in a substance from the decomposition of potassium.

This is relatively easy because argon, being an inert gas, usually does not leech out of a mineral and is easy to measure in small samples. The actual date is comprised of the time it has been formed from molten/heated minerals. This method, therefore, is not very useful when dating the time a human bone has been in the ground, but it does help in giving the time of many of the artifacts that are often times found alongside burials.