The magnetic North Pole has shifted over the millennia, leaving clues in the minerals that make up clay antiquities

Study co-author Lisa Tauxe inserts samples into a thermal demagnetizer. Scripps Institution of Oceanography at UC San Diego

Forgers, beware. Researchers just discovered how to determine whether any piece of pottery is ancient or not—by reading its magnetic signatures.

A team at the Scripps Institution of Oceanography at the University of California, San Diego, details their new method in a study published this week in the Proceedings of the National Academy of Sciences .…