Billon (alloy)
Billon is an alloy made by mixing a precious metal, usually silver (sometimes gold), with mostly base metal like copper. It is used mainly to make coins, medals, and token coins. The word comes from the French bille, meaning log.
People have used billon since ancient times, from Greece through the Middle Ages. In 6th–5th century BC, some cities on Lesbos minted coins that were about 60% copper and 40% silver. Over time, many billon mixes had very little silver, sometimes less than 2%.
In the Roman Empire, billon coins were common as silver content dropped and bronze content rose in the 3rd century AD. By the end of the 3rd century, many coins were almost all bronze with only a thin wash of silver.
In the 18th century, German states issued billon coins with silver content up to about 37% for fractional denominations.
Modern examples include:
- US Jefferson nickels from 1942–1945, made of 35% silver, 56% copper, and 9% manganese to save other metals; they are recognizable by their color and a large mintmark above the Monticello dome.
- Mexican one peso coins from 1957–1967, made of 10% silver, 70% copper, 10% nickel, and 10% zinc.
This page was last edited on 3 February 2026, at 14:37 (CET).