Find out why weapons Terracotta army of Qin Shi Huang still shiny and sharp after more than 2000 years

Scientists solve the mystery of China's terracotta weapons

For decades, scientists have been unable to explain why the weapons of the terracotta army in the tomb of Qin Shi Huang are so perfectly preserved, their surfaces are still shiny. and sharp after being buried for more than two millennia.

Terracotta warriors and horses stand inside pit # 1 of the Terracotta Warriors and Horses Museum in Xi'an, Shaanxi Province, China

The research by an international team of scientists published Thursday could solve the mystery and put an end to an intriguing hypothesis that has lasted for four decades: that ancient Chinese artisans Dai used an unexpectedly advanced method of preservation, using chromium metal.

After studying 464 brass weapons and accessories, the scientists concluded that almost perfectly preserved weapons, including mirrors, spears, and spears, were accidental - a combination of favorable soil composition in the catacombs and high tin content in copper metal.

Scientists claim that chromium was found on the surface of copper weapons coming from the chrome-rich lacquer that was smeared by artisans on terracotta statues and weapon parts. They have no intention of using chromium for preservation purposes.

The terracotta army is composed of thousands of life-sized earthen warriors, horses and chariots and bronze weapons that were part of the tomb of Qin Shi Huang - the first emperor of China to unify. , located near Xi'an city. The tomb complex was discovered in 1974 and it represents one of the greatest archaeological discoveries of the 20th century.

Scientific analysis nearly four decades ago uncovered chromium on the surface of some weapons, suggesting that the ancients used chrome-based treatments to prevent corrosion.

Chrome coating, a technology discovered in the early 20th century, was used to process metals to prevent them from corroding. The metal will be dipped in a solution containing chromium salt. A layer of chromium oxide is deposited on the metal surface, creating an anti-rust barrier.

Marcos Martinón-Torres, an archaeologist at the University of Cambridge and the head of research published in Scientific Reports, said: "The lacquer is applied to the terracotta army as a primer before they are painted in different colors and we think it is also applied to decayed wooden parts such as handles and shafts. "

Ancient bronze coins were often in poorly preserved state, with porous, porous surfaces in green or dark colors.

"In essence, we show that the terracotta army's weapons show the state of protection," said Martinón-Torres, a researcher at the University College London in collaboration with the Qin Shi Huang Tomb Museum. well managed, but currently there is no indication that this is anything but a result of accidental "