CHINA: One of the most remarkable aspects of the Terracotta Army is the pristine state of the soldiers’ bronze weapons after 2,000 years underground. Because trace amounts of chromium have been detected on the blades, scientists have long presumed that ancient Chinese craftsmen invented a type of anti-rust coating. However, researchers have learned that the chromium is actually contamination from lacquer applied to the weapons’ handles and shafts, and is not responsible for the metal’s preservation. It is now thought that the chemical composition of the surrounding soil helped prevent corrosion.