Fission track dating

When uranium decays, subatomic particles split away. The particles leave tiny tracks in the crystal structure of minerals such as zircon and apatite.

Name: Fission track dating

Material used: Volcanic glass, zircon and other crystals

Age range: 10,000 to 500 million years ago

How it works: Measures radioactivity by counting tracks left in crystals by decaying uranium atoms