How are igneous rocks the best type of rock sample for radiometric dating?

Igneous rocks are the best type of rock sample for radiometric dating because they form from the solidification of molten material, which allows them to incorporate radioactive isotopes at the time of their formation. This process creates a closed system where the parent isotopes and their decay products remain isolated from external influences, providing a clear record of the time since the rock crystallized. Additionally, the predictable decay rates of isotopes, such as uranium-lead or potassium-argon, enable precise age determinations. This makes igneous rocks particularly valuable for dating geological events and understanding the timing of Earth's history.