New Magnetic Method Detects Fake Ancient Pottery

Key facts

• Researchers at Scripps Institution of Oceanography, UC San Diego, developed a method to authenticate ancient pottery using magnetic signatures.
• The study was published in the Proceedings of the National Academy of Sciences.
• The method relies on thermal remanent magnetization (TRM) and viscous remanent magnetization (VRM).
• Clay fired in ancient times has TRM pointing in a different direction than modern pottery due to Earth's shifting magnetic pole.
• VRM is a weaker secondary signal acquired over centuries, often treated as noise.
• The team tested 45 pottery samples, including ancient shards, royal Judean storage jars, modern pottery, and souvenirs.
• Heating samples in increments of 18°F, they found VRM in objects older than a millennium disappears only above 234°F.
• The method was applied to three artifacts of questionable authenticity from the Israel Antiquities Authority, all found to be ancient.
• The technique could help museum curators, archaeologists, and law enforcement combat forgery and illicit antiquities trade.
• The study mentions the 'James Ossuary' case, where forgery was not proven beyond reasonable doubt.