Tumbaga
Mythological · Uncommon · Ancient
A gold-copper alloy developed independently across multiple Pre-Columbian civilizations. Its most remarkable property is depletion gilding: when treated with acidic plant juices, the copper surface dissolves, leaving a pure gold exterior over the alloy core.
Identity
- Source
- Pre-Columbian Mesoamerican and Andean civilizations
- Aliases
- Guanín, Sacred alloy
Physical Properties
- Appearance
- Warm reddish-gold surface over a copper-rich core; acid-treated pieces show pure gold exteriors
- Luster
- Metallic
- Density
- 11 g/cm³
- Melting point
- 950 °C
- Boiling point
- 1800 °C
- Lighter
- Uru
- Denser
- Adamantium
- Magnetism
- Non-magnetic
- Electrical conductivity
- High
Mechanical Properties
- Mohs hardness
- 3.5
- Tensile strength
- 300 MPa
- Softer
- Shakudo
- Harder
- Hepatizon
- Workability
- Easy
- Brittleness
- Moderate
- Malleability
- Very High
- Ductility
- High
Chemical Properties
- Corrosion resistance
- moderate
- Reactivity
- low
Lore & Narrative
Spanish conquistadors were baffled to find objects that looked like solid gold but weighed far less. The transformation process, turning copper-gold into what appeared to be pure gold, was interpreted as a form of alchemy.
- Notable uses
- Ritual masks, votive figures, jewelry, El Dorado offerings
- Forge uses
- masks, figurines, jewelry
- Worldbuilding traits
- alchemical, transformation, sacred, precolumbian
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