Gold and items made from it continue to fascinate now as they did 500 years ago when conquistadores first landed on the shores of the Americas. The metal was used by most cultures in the Americas, from Mexico south to Argentina. Although the level of craftsmanship varied considerably, techniques used in the New World were virtually the same as those utilized by craftsmen in the Old World, with the exception of vitreous enameling. The reasons for these parallels in cultural technologies are basic.
Gold, silver, and copper are easily worked with very simple technology. In fact, gold and silver are the two most malleable metals on earth. Pre-Hispanic goldsmiths utilized extremely dense, hard stone hammers (e.g. of magnetite) without handles; stone anvils; chisels; and chasing tools made of gold/copper alloys to cut and chase the gold. These tools no doubt were augmented by tools made of wood, bone, and leather.
With the addition of braziers to hold charcoal fires—and the use of long bamboo tubes, with ceramic tips, blown through to make the fires much hotter—metalworkers were able to make binary and ternary alloys, and to melt them into ingots from which they could forge sheet and wire—the raw stock necessary to manufacture some of the pieces that we see today in museums and that dazzled the conquistadores when they arrived.
Less important metals were platinum and lead. Platinum occurred in the southern Colombia/northern Ecuador borderland. Its extremely high melting point limited its use to what could be termed small experimental pieces. Lead was employed for ore extraction, probably of silver, in the southern half of Peru and northern Bolivia; other uses of lead have not been well documented.
The need to adorn the body with gold nuggets gathered from streams may well have been the earliest use of gold by Brazilian and other South American cultures, although much additional research remains to be done. It is certain that humankind's fascination with gold promotes its use as soon as it is introduced into a culture.
Sophisticated sheetmetal pieces were being made on the South American continent as early as 1500–1000 b.c. in the north coast culture known as Cupisnique. North coast Peru has also yielded evidence of gold fabricated into very complex pieces as early as 700–800 bce. The La Tolita area of Ecuador/Colombia has yielded dates from 400 bce–200 ce. It would seem likely from these dates that from about the time of Christ, gold working was moving northward in Colombia into Panama and thence Mexico, since reliable dating gets later as one moves north.
There were two loci of gold working in South America. One was the direct working characterized by Peruvian smiths. The other was indirect working of the gold characterized by the refined and intricate lost-wax cast designs of the goldsmiths in Colombia.
In Peru, the goldsmiths' industry tended to make mainly sheet and wire. The Peruvian cultures inclined toward large ceremonial or showy pieces (e.g., large ceremonial masks and very large raised gold vessels), with only small quantities of personal body adornment. Nowhere else on the continent were the technically more difficult direct metal-working techniques carried to such advanced extremes as in Peru.
Direct working of the metal involved forming by hammering and cutting individual parts that were then assembled with mechanical (e.g., strap and slot, tab and slot) or thermal joins. This is called fabrication. The major fabrication techniques used by pre-Hispanic goldsmiths were forging sheet and wire, raising vessels, chasing and repoussé, real filigree, granulation, proto-brazing, and depletion gilding. The cultures most associated with these techniques were on the north coast of Peru (e.g., Mochica and Sicán).
The Colombian smiths seemed to respond artistically to the indirect approach of fashioning the work in wax, to be cast in gold. It allowed them to fashion lovely small-scale cast pieces. Though the indirect approach certainly yielded some very large cast pieces, there was more preoccupation with personal, decorative body adornment such as necklaces, earrings, nose rings, and labrets. Many examples abound to show that Colombian goldsmiths knew direct metalworking techniques. However, their fascination with lost-wax casting, and the plenteous supply of beeswax available, certainly allowed them to master the indirect approach to metalwork; this skill was carried up into Mexico.
Indirect working of gold by lost-wax casting was done by making the piece in wax and then coating it with a liquid refractory material composed of caliche, powdered charcoal, and lime. When the refractory hardened, like plaster, the mold was placed in a heat source, the wax is eliminated; then molten metal could be poured in. After cooling, the refractory was broken away, revealing the casting piece. It could then be finished and polished. The cultures most associated with this technique are Costa Rica (Diquis), Panama (Coclé, Chiriqui'), and Colombia (Sinu', Muisca).
Studies of pre-Hispanic metalwork have been hampered by the conquistadores' massive looting, which virtually eliminated metalwork from Mexico, and grave robbing, which still occurs despite efforts to control it. This has affected efforts to locate workshop sites and undisturbed tombs so they may be scientifically excavated and the maximum information gleaned from their contents to aid in the understanding of the work and life of these ancient peoples.
Surveys of ancient and modern techniques are in Oppi Untracht, Jewelry Concepts and Technology (1982). A more complete discussion of Peruvian goldsmithing techniques is in Heather Lechtman, "Traditions and Styles in Central Andean Metalworking," in The Beginning of the Use of Metals and Alloys, edited by Robert Madden (1988), pp. 344-378, and Izumi Shimada and Jo Ann Griffin, "Precious Metal Objects of the Middle Sican," in Scientific American, 270 (April 1994): 82-89. See also Julie Jones, ed., The Art of Precolumbian Gold (1985).
Hearne, Pamela, and Robert J. Sharer, eds. River of Gold—Precolumbian Treasures from Sitio Conte. Philadelphia: University Museum, University of Pennsylvania, 1992.
McEwan, Colin, ed. Precolumbian Gold: Technology, Style, and Iconography. Chicago: Fitzroy Dearborn Publishers, 2000.
Mayr, Juan, and Clara Isabel Botero. The Art of Gold, the Legacy of Pre-Hispanic Colombia: Collection of the Gold Museum in Bogotá. México, D.F.: Fondo de Cultura Económica; Bogotá: Banco de la República; Milano, 2007.
Jo Ann Griffin