Advanced Stone-Polishing Techniques Employed Earlier Than Thought Chinese craftsmen used diamonds and sapphire to polish tools thousands of years earlier than previously believed, according to new research findings. Robert Siegel talks with Peter Lu, a physics graduate student at Harvard, who applied advanced material science microscopes and tools to ancient Chinese artifacts.

Advanced Stone-Polishing Techniques Employed Earlier Than Thought

Advanced Stone-Polishing Techniques Employed Earlier Than Thought

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Diamond-polished corundum axe from the Neolithic Liangzhu culture of ancient China, ca. 2500 B.C. Peter J. Lu hide caption

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Peter J. Lu

Diamond-polished corundum axe from the Neolithic Liangzhu culture of ancient China, ca. 2500 B.C.

Peter J. Lu

Chinese craftsmen used diamonds and sapphire to polish tools thousands of years earlier than previously believed, according to new research findings. Robert Siegel talks with Peter Lu, a physics graduate student at Harvard, who applied advanced material science microscopes and tools to ancient Chinese artifacts.

Lu says the finding rewrites ancient Chinese history "from a technological standpoint."

"Somehow, in the Stone Age… they were able to sort particles that were less than a millionth of a meter across," he says.

Lu's findings were published in the journal Archaeometry.