Knife, 8th-10th century, 7 1/8 x 4 5/16 x 1/4 in. (18.1 x 10.95 x 0.64 cm), Bronze, Peru, 8th-10th century, A tumi is a knife with a flared, semicircular blade that was used in ceremonies throughout the ancient Andes. Lambayeque artists working in northwest Peru made especially dramatic and opulent examples for elite members of society. Lambayeque metalworkers were technologically advanced; they developed a unique type of bronze by alloying copper and arsenic, from which this blade was cast. Originally, this tumi was likely capped by an elaborate finial depicting an important Lambayeque deity, known as the Sicán Lord, executed in materials such as gold, silver, and turquoise