A MANGBETU IRON AND IVORY 'TRUMBASH' CEREMONIAL KNIFE, SUDAN The sickle-shaped blade set in an ivory handle decorated with grooves and dot-and-circle motifs, 33cm long Literature: Trumbash knives were used both as a symbol of rank and as currency. Copper or brass blades were reserved for the aristocracy and examples of iron with ivory handle, such as this one, were only for the most important members of the royal family. For a discussion of trumbash knives, cf. C.J. Opitz, An Ethnographic Study of Traditional Money, Ocala, 2000, p.357.