Scientists Develop Method to Detect Fake Ancient Ceramics

Scientists have developed a way to test ancient ceramics for signs of forgery by studying the magnetic record trapped in clay during firing.

The method, developed by researchers at the Scripps Institution of Oceanography at the University of California, San Diego, uses two forms of magnetism preserved in ceramic particles. Larger particles retain a stable imprint of the Earth’s magnetic field after the object cools. Smaller particles carry a weaker signal that continues to fluctuate over centuries, a phenomenon known as viscous magnetism.

The researchers found that reheating a ceramic object can remove the viscous signal. The newer the object, the lower the temperature required. To test the method, they heated ceramics ranging from objects thousands of years old to items bought in Jerusalem souvenir shops and known fakes. The temperatures began at 50°C and increased gradually.

Samples more than 1,000 years old lost their viscous magnetism only above 112°C, while modern samples lost the signal at lower temperatures. The findings appeared in the journal PNAS.

Lead researcher Yoav Vaknin said the technique could assist museum conservators, archaeologists, historians and authorities fighting the illicit antiquities trade, archaeological-site looting and forgery. The researchers also propose using it as evidence in court cases involving alleged fakes and plan to apply it to questionable objects in museums worldwide.

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Conservators, archaeologists and historians, and authorities fighting the illicit trade in antiquities, the looting of archaeological sites and forgery.