 As well as porcelain, a wide range of materials that were more valuable were worked and decorated with great skill for a range of uses or just for display.Chinese jade was attributed with magical powers, and was used in the Stone and Bronze Ages for large and impractical versions of everyday weapons and tools, as well as the "bi" disks and "cong" vessels.Later a range of objects and small sculptures were carved in jade, a difficult and time-consuming technique.