Technological and material features of the gold work of Mesoamerica

Abstract

Technological and material features of the gold work of Mesoamerica Caractéristiques technologiques et matérielles du travail de l'or en Mésoamérique

The Case for the Aztec Goldsmith

“…Ornaments made to be worn, and ones made by the lost-wax process, would have benefited from a higher copper content that provides greater rigidity and better casting quality. Thus the metallurgical composition of one collection of Aztec-style gold objects does have a higher copper content than those in the Tlaltecuhtli offerings and overlaps that of objects from the Valley of Oaxaca (Ruvalcaba Sil et al 2009). Also an analysis of gold and silver artifacts from Monte Albán's Tomb 7 concluded that some Aztec pieces do share the Mixtec metallurgical features (Peñuelas et al 2011:627) as shown in Figure 11.…”

Metalworking at Mayapan, Yucatan, Mexico: Discoveries From the R-183 Group

“…Copper-lead alloys melt at lower temperatures than pure copper, allowing the metal to fill mold cavities completely and easily, and increasing the likelihood of successful castings for small, intricate objects such as bells and filigree ornaments (Hosler 2013:239). In copper alloys from the Valley of Mexico, trace amounts of lead are often co-present with tin, arsenic, and/or silver; for example, copper alloy bells from the Aztec Templo Mayor have an average of 2.92% arsenic, 2.34% tin, and 3.86% lead (Schulze 2008:Table 1), while a metal chisel from the Valley of Mexico, found in Morelos, had a composition of 1.23 wt% arsenic, 4.35 wt% tin, and 0.66 wt% lead (Hosler 1994:Table 7.2). Silver is another alloying metal that was often used in late West Mexican metallurgy, which became common after a.d. 1100, particularly at Tarascan sites (Grinberg 1989; Hosler 1994:140, 2013:229; Pollard 1987), and in the Mixtec metalworking traditions of the Central Valleys of Oaxaca, particularly in the offerings of Monte Albán Tomb 7 (Ruvalcaba Sil et al 2009). Concentrations of above 7.0 wt% silver in copper alloy add strength and toughness to the materials, as well as creating silvery colors that are manifested using surface enrichment techniques (Hosler 1994:113).…”

“…Concentrations of above 7.0 wt% silver in copper alloy add strength and toughness to the materials, as well as creating silvery colors that are manifested using surface enrichment techniques (Hosler 1994:113). Concentrations for some ornaments reached between 20 wt% silver in Mixtec metalworking (Ruvalcaba et al 2009:294) and 55 wt% silver in Tarascan metalworking (Grinberg 1989).…”

“…Silver is another alloying metal that was often used in late West Mexican metallurgy, which became common after a.d. 1100, particularly at Tarascan sites (Grinberg 1989; Hosler 1994:140, 2013:229; Pollard 1987), and in the Mixtec metalworking traditions of the Central Valleys of Oaxaca, particularly in the offerings of Monte Albán Tomb 7 (Ruvalcaba Sil et al 2009). Concentrations of above 7.0 wt% silver in copper alloy add strength and toughness to the materials, as well as creating silvery colors that are manifested using surface enrichment techniques (Hosler 1994:113).…”

“…Notably, copper-silver alloys are absent in the assemblage, although they were important in West Mexican (Grinberg 1989; Hosler 1994:113) and Oaxacan metallurgy (Ruvalcaba Sil et al 2009). Although many Mayapan objects have trace amounts of silver, the maximum concentration is 0.42 wt% silver, which is below the concentration needed to significantly affect hardness or optical properties (Hosler 1994).…”