metallurgy: The Americas 655 The goldsmiths of Sipán were masters at combining gold or copper with shell and stone, as exemplified by a massive owl headdress The owl at the center of the headdress is three-dimensional, its eyes inlaid with white shell and turquoise Goldsmiths attached bangles to the owl’s large gold wings with gold wire, an ensemble that must have created impressive sounds and reflected light as the priest walked in procession The explosion of creativity that took place after 500 c.e throughout Central America, in Costa Rica, and in Panama was mostly influenced by developments in Colombia Gold and copper were abundant in Panama, where gold indicated status, both in life and death Panamanian metalsmiths worked in tumbaga, an alloy with a high percentage of copper mixed with gold These artisans embossed gold plaques with representations of fantastic creatures Human and animal figural pendants were also formed in lost wax, as was the openwork, or false filigree, that ornamented these works In Costa Rica gold casting began around 500, with influences from Panama and Colombia Costa Rican goldsmiths were adept at depletion gilding, a technique that produced a seamless surface layer of gold A good example of this kind of work, a frog pendant from Chaparrón, was first formed of tumbaga The goldsmith removed the surface copper by heating the piece in an open hearth until the copper oxidized He then used a plant-based acid solution to dissolve the black oxidized copper from the surface, leaving behind a thin layer of almost pure gold that could be burnished to a high finish After 500 in the Caribbean lowlands of Colombia, Zenú caciques, or leaders of chiefdoms, had become powerful and resourceful and were commissioning gold adornments to indicate their status Near important sources of raw gold, the Cauca and Nechí rivers, Zenú metalsmiths mastered gold casting and depletion gilding The artisans imitated the appearance of plumage on the figure of a bird by using false filigree and cast-wire swirls and spirals The Zenú also embellished wooden idols with sheets of gold Twenty-four of these idols were discovered in a temple in the ceremonial center at Finzenú A significant development among the Zenú was that a portion of the gold production was meant for trade, for Zenú pieces have been discovered at some distance In the Cordillera Oriental mountain range of Colombia, the Tairona and Muisca people had very different approaches to metalsmithing For the Muisca (after 800), votive objects in gold with copper alloy were cast in the lost-wax technique, but with a difference These artisans used a stone matrix, with several designs carved in high relief on one stone The carving was impressed into the clay, which when dry was coated with beeswax on the outer surface The wax was impressed with the stone relief, thus creating a negative and positive imprint in the wax Several objects could be produced from the one wax model, imprinted with different designs from the single stone In contrast to the Muisca, the Tairona goldsmiths created elaborate clay core images that were destroyed at the time the mold was broken open and the gold object removed The Tairona were less interested in producing multiples and more focused on a refined finished piece These pendants are highly symbolic, very unlike the simpler votive figures of the Muisca In the northern coastal region of Peru, the Sicán (after 900) had access to copper and arsenic-bearing ore deposits They could acquire gold and silver from the northern highlands The Sicán metalsmiths worked in high-carat gold alloys, silver, arsenical bronze, silver alloyed with copper, and tumbaga They added small amounts of arsenic to improve the hardness and malleability of copper, giving the metal a silvery appearance These artisans were particularly adept at producing gold sheets and enhancing their designs with repoussé, chasing, and joining In one Sicán tomb, archaeologists found thousands of depletion-gilded tumbaga squares that had originally been sown onto a costume, creating a resplendent display The Sicán metalsmiths also did surface depletion of silver from gold Masks and ceremonial headdresses are indicative of the sophistication reached by these artisans, in terms of alloying, combining metals and stones, and of their technical expertise Movement and articulation became part of the design of the piece One headdress, measuring feet high by feet wide, included gold bangles, some with turquoise inlay, portrait heads of deities cut from silvery-colored gold alloy sheets, feline heads of gold alloy, and the mask itself, which was made up of several sheets of gold and tumbaga The Chimú, at their capital of Chan Chan on Peru’s north coast, developed (after 1000) a distinctively elegant and aesthetic approach to gold ornament and jewelry Meant for ostentatious display for the Chimú nobility, most pieces were produced from gold sheets Reflective of this preference is a pair of ear spools, each comprising more than 100 tiny gold pieces, soldered or stapled into a profuse and extravagant pattern Chimú goldsmiths also mastered the technique of granulation They cut out small pieces from a gold sheet, placing them on a heated charcoal block During the melting process, surface tension caused the gold pieces to become spheres To adhere the tiny beads to a gold surface, the Chimú used copper-salt reduction or reaction soldering In this technique the granules were placed on an organic glue that had been mixed with a finely ground copper salt, like malachite With heat, the glue burned off and the copper salt was reduced to metallic copper in a liquid state At the points where the granules