The Warriors are made of terracotta, a type of fired clay.
这些勇士由陶制成，陶是一种烧制过的粘土。
英语百科
Fire clay
Fire clay is a range of refractory clays used in the manufacture of ceramics, especially fire brick. The United States Environmental Protection Agency defines fire clay very generally as a "mineral aggregate composed of hydrous silicates of aluminium (Al2O3·2SiO2·2H2O) with or without free silica."