text: Metal smiths demonstrated increasing technical sophistication, producing both utilitarian and status-linked items. During the latter phase, Michoacán emerged as a technological hub, with metal artifacts also appearing at the adjacent zones of Guerrero and Jalisco. 
  Alloys became more prevalent during the second phase, as metal workers experimented with color, strength and fluidity. Formerly utilitarian assemblages transformed, with new focus placed upon metallic status objects. Further, the appearance of a copper-tin bronze alloy suggests contact between West Mexico and Peru during this period. However, many of the alloys/alloy concentrations used in West Mexico appear to reflect local innovation. 
  Scholars such as  Dorothy Hosler suggest that ancient Mesoamericans were unique in their attention to the peculiar aesthetic properties of metals, such as the brilliant sounds and colors evoked through the movement of metallic objects. The rather late emergence of metallurgy in ancient Mesoamerica likely contributed to its novelty and subsequent role as a marker of elite status. 
  It has been suggested that Mesoamerican metal smiths produced particular alloys with the chief aim of exploiting the alloys’ emergent color properties, particularly the vivid gold tones produced through infusion of tin, and the silver shades that develop at high arsenic concentrations. Notably, certain artifacts from West Mexico contain tin or arsenic at concentrations as high as 23 weight percent, while concentrations of alloying elements at roughly 2 to 5 weight percent are typically adequate for augmented strength and mechanical utility.
  Metal smiths in pre-Columbian West Mexico particularly exploited the brilliance inherent in metallic sound and sheen, suggesting that their creations tended to occupy a sacred and symbolic space. Metallic colors, gold and silver, might have been connected with solar and lunar deities while bell sounds have been associated with fertility rituals and protection in warfare.