How Stone Age scalpels are still cutting it in modern surgery

Updated 9:04 AM ET, Tue September 27, 2016
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Obsidian -- a type of volcanic glass -- can produce cutting edges many times finer than even the best steel scalpels. Courtesy of Dr Lee Green
At 30 angstroms -- a unit of measurement equal to one hundred millionth of a centimetre -- an obsidian scalpel can equal diamond in the fineness of its edge. Courtesy of Dr Lee Green
Mesoamerican cultures such as the Mayans and the Aztecs sometimes performed human sacrifices using obsidian blades. Courtesy of Simon Burchell
Unlike steel scalpels, which have a microscopically jagged edge, obsidian cleaves into a fine and continuous edge when properly cut. Getty Images
Trepanation -- the practice of cutting a hole in the skull -- was performed using obsidian tools by Neolithic cultures, although its purpose remains unknown. This skull in Lausanne Museum, in France, shows signs of bone regrowth, meaning the patient survived the operation. Courtesy of Rama