Jeungdo Gaza, known as the oldest metal type, turns out to be faked

Jeungdo Gaza, which saw raised suspicions over its authenticity as the oldest metal type in the world, has turned out to be faked. With this new founding, the 5-year long controversy over whether it was invented 138 years earlier than Jikji (1377), currently known as the oldest metal type, will come to an end.

The National Forensic Service announced on Monday that it found evidence of manipulation through the 3D metal CT scans on seven Goryeo metal types including Jeungdo Gaza. "Through the CT scans and chemical test results, there is a high possibility that the types are counterfeited, not created by the traditional casting method of the Goryeo Dynasty", the agency said.

The results showed additional layers covering the surfaces of the seven metal types evenly. This means that they are covered by a layer of substance that has different density from the other parts. "In normal cases metal types cannot be double-layered since they are produced under single casting process", said Kang Tae-yi, a researcher of National Forensic Service. "It seems that somebody covered the surface with a different substance to make them look old and corroded".

The analysis has confirmed that the inner parts of the metal types in question are composed of 20-22 percent of copper and 55-56 percent of tin, while the outside parts are composed of 30-31 percent of copper and 47-49 percent of tin. Moreover, there are traces of patches at the back of two of the questioned metal types.

This result is likely to spur issues on the poor verification process of the National Research Institute of Cultural Heritage, an institution under the Cultural Heritage Administration. The institute had concluded in their report released in November last year that among the seven metal types preserved in the Cheongju Early Printing Museum, three are Jeungdo Gaza, four are Goryeo metal types. Experts point out that reinvestigation should be held for the metal type possessed by Kim Jong-chun, the head of Korean Antique Association, which was also categorized as Jeungdo Gaza.