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Why do gold alloys make better coins and jewelry than pure gold?
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gold
The precious metal gold is a chemical element with the symbol Au. Its square on the periodic table details some of its properties, including its atomic weight, atomic number, and crystal structure.
Pure gold is naturally very soft, making it susceptible to wear and deformation during prolonged handling. Because of this, it is alloyed with other metals to improve its utility for items that require durability.12
The primary reasons for creating gold alloys include:
- Increasing Hardness and Strength: By adding metals such as silver, copper, nickel, or zinc, the material gains the necessary hardness and structural strength to resist damage when used in jewelry or coinage.123
- Reducing Costs: Alloying gold with less expensive base metals helps lower the overall cost of the final product while maintaining the desired aesthetic qualities.4
- Customizing Appearance: The color of gold can be modified through alloying; for example, adding silver, copper, and zinc can produce various shades of yellow gold, while adding nickel, copper, and zinc creates white gold.1
The gold content in these alloys is measured in karats, where 24-karat gold is considered pure (more than 99 percent gold), and lower karat values indicate a higher proportion of alloying metals.14