Billon (alloy)

Billon /ˈbɪlən/ is an alloy of a precious metal (most commonly silver, but also gold) with a majority base metal content (such as copper). It is used chiefly for making coins, medals, and token coins.

Billon dirham of Abbad II al-Mu'tadid, dated 439 AH (1047–1048 CE)

The word comes from the French bille, which means "log".[1]


The use of billon coins dates from ancient Greece and continued through the Middle Ages. During the sixth and fifth centuries BCE, some cities on Lesbos used coins made of 60% copper and 40% silver. In both ancient times and the Middle Ages, leaner mixtures were adopted, with less than 2% silver content.[2][3]

Billon coins are perhaps best known from the Roman Empire, where progressive debasements of the Roman denarius and the Roman provincial tetradrachm in the second century CE led to declining silver and increasing bronze content in these denominations of coins. Eventually, by the third quarter of the second century CE, these coins were almost entirely bronze, with only a thin coating or even a wash of silver.[4]

See alsoEdit


  1. ^ "Billon". (Unabridged (v 1.1) ed.). Random House, Inc. Retrieved 25 September 2009.
  2. ^ Harl, Kenneth (19 March 1998). "Early Medieval and Byzantine Civilization: Constantine to crusades". Tulane University. Archived from the original on 15 October 2009. Retrieved 25 September 2009.
  3. ^ Munro, John (15 January 2007). "Earl J. Hamilton, American Treasure and the Price Revolution in Spain, 1501–1650". Book Review. Economic History Services. Archived from the original on 18 September 2009. Retrieved 25 September 2009.
  4. ^ Christiansen, Erik (2004). Coinage in Roman Egypt: The hoard evidence. Aarhus University Press. p. 135–141.