Electrum
Alloys · Rare · Ancient
A naturally occurring gold-silver alloy found in riverbeds and deposits, electrum was used for coinage and ornamentation long before pure gold could be reliably refined. The first coins in history, the Lydian staters, were struck in electrum around 600 BC.
Identity
- Source
- Natural and historical alloy: gold and silver
- Composition
- Gold 20-80%, Silver, Copper
- Over time
- Found in nature as an alloy of gold and silver with traces of copper, and also made by hand. The Lydian electrum coins of about 600 BC held roughly 45 to 55% gold.
- Also known as
- Green gold, White gold (archaic), Asem (Egyptian)
- Ores, before industry and since
- Gold (Gold), Sylvanite (Gold), Acanthite (Silver), Chlorargyrite (Silver), Freibergite (Silver), Galena (Silver), Proustite (Silver), Pyrargyrite (Silver), Silver (Silver), Tetrahedrite (Silver), Azurite (Copper), Chalcocite (Copper), Chalcopyrite (Copper), Copper (Copper), Malachite (Copper), Tetrahedrite (Copper)
- Ores of the industrial age
- Calaverite (Gold), Bornite (Copper), Chrysocolla (Copper), Covellite (Copper), Cuprite (Copper), Enargite (Copper)
Physical Properties
- Appearance
- Pale yellow-gold, lighter in color than pure gold, naturally occurring or deliberately alloyed
- Luster
- Metallic
- Density
- 15 g/cm³
- Melting point
- 1000 °C
- Boiling point
- 1900 °C
- Lighter
- Ebony
- Denser
- Rose Gold
- Magnetism
- Non-magnetic
- Electrical conductivity
- Very High
Mechanical Properties
- Mohs hardness
- 3
- Softer
- Zinc
- Harder
- Bronze
- Workability
- Easy
- Brittleness
- Tough
- Malleability
- Very High
- Ductility
- Very High
Chemical Properties
- Corrosion resistance
- Very High
- Reactivity
- Very Low
Lore & Narrative
Ancient Egyptians called electrum asem and valued it above gold for certain ritual purposes. The tips of Egyptian obelisks, Cleopatra's Needles among them, were traditionally capped with electrum to catch and reflect the rising sun.
- Notable uses
- First coins, obelisk tips, ritual vessels, jewelry
- Forge uses
- Coinage, Ritual objects, Jewelry
- Worldbuilding traits
- Ancient, Natural, Solar, Monetary
Sources
- Electrum, Wikipedia
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