CyI Professor and STARC Director Prof. Thilo Rehren was part of a team that solved a long-standing mystery in archaeology: for four decades, researchers believed the 2,200-year-old bronze weapons of the Terracotta Warriors in China were amazingly preserved because they were chrome plated.

Not so, according to this new research. The chrome plating derives from a decorative varnish rather than a preservation technique. The international team of researchers show that the chromium found on the bronze surfaces is simply contamination from lacquer present in adjacent objects, and not the result of an ancient technology. The researchers also suggest that the excellent preservation of the bronze weapons may have been helped by the moderately alkaline pH, small particle size and low organic content of the surrounding soil.

The research, published in Nature Scientific Reports, has received widespread publicity including Phys.org and National Geographic: 

https://phys.org/news/2019-04-scientists-mystery-terracotta-army-weapons.html

https://www.nationalgeographic.com/culture/2019/04/ancient-terracotta-warrior-chrome-weapon-theory-debunked/

You can download the full paper (pdf) at the following link: