How Fast Is Uranium in Rock (diffusion)?

Heavy radioactive elements like uranium diffuse through solid rock at glacial atomic rates over enormous spans of time. This slow migration through crystal lattices is essential to radiometric dating — letting geologists determine the ages of ancient rocks with remarkable precision.

Slower than essentially anything you can see moving with the naked eye.

• Roughly 3× faster than stalagmites grow
• Still 100× slower than fingernails grow