Discoveries of people using gold in South America date back to 1600 BC. The use of gold spread upward to Central America by 200 to 400 AD. Around 800 AD, the Mixtec learned the craft and became goldsmiths for the Aztec.
From around 400 to 600 AD in the Panama and Costa Rica region, goldsmiths used a technique called "tumbago," which involved mixing less valuable metals such as copper with gold to create the look of high-carat, purer gold.
Hall of Mexico and Central America