Researchers Spot Fake Ancient Pottery Using the Earth's Magnetic Field

Researchers have developed a new method to distinguish between ancient and modern pottery using the Earth's magnetic field. This technique, published in the Proceedings of the National Academy of Sciences, could aid in identifying fraudulent archaeological artifacts. When clay particles are heated in a kiln, they acquire a magnetic signal called thermal remanent magnetization (TRM) that points toward Earth's magnetic North Pole.

Over time, the clay's minerals also acquire a weaker magnetic signal called viscous remanent magnetization (VRM). While scientists have known about VRM for over a century, it was often disregarded as "noise." The new method involves heating pottery samples and measuring when the VRM signal disappears, revealing if they are ancient or modern.

The researchers found that pottery older than a millennium requires heating to at least 234 degrees Fahrenheit to erase its VRM signal. Modern pottery's VRM can be wiped at lower temperatures. The technique could help museums, archaeologists, historians, and law enforcement authorities differentiate between genuine and forged artifacts.

The method was tested on pottery samples from various origins, with three artifacts of questionable authenticity passing the test. This discovery may prove useful in detecting looted artifacts and combating the illicit antiquities trade.