Chemistry unearths the secrets of the Terracotta Army

As the sun rose over the fields of Xi’an, Shaanxi Province on the 29 March 1974, a group of Chinese farmers set off for a day’s toil unaware of the astounding discovery they were about to make. There had been reports of fragments of terracotta figures in the past, but as the farmers dug a water well that morning they uncovered one the greatest archaeological sites in the world.

One can only imagine the intrigue and bemusement they must have felt when, after digging 5 m down into the loess sediment that had accumulated over the past 2000 years, they suddenly saw terracotta faces peering up at them. The first of an estimated 8000 Terracotta Warriors were emerging from the necropolis.

Fast forward 40 years and the home of the Terracotta Army is a world famous tourist attraction with more than a million visitors annually. Additionally some of the warriors and their horses have been on sell out world tours, attracting more fans than a One Direction concert.

Forty years of painstaking recording and investigation has taught us much about this site, but in recent years archaeologists have turned to chemistry to help provide new evidence about how these workers constructed the Terracotta Army.