Billon (alloy)
Encyclopedia
Billon is an alloy
of a precious metal
(most commonly silver
, but also mercury
) with a majority base metal content (such as copper
). It is used chiefly for making coin
s, medal
s, and token coin
s.
The word comes from the French
bille.
The use of billon coins dates from ancient Greece
and continued through the Middle Ages
. During the 6th and 5th centuries BC, some cities on Lesbos Island
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.
Billon coins are perhaps best known from the Roman Empire
, where progressive debasement
s of the Roman denarius
and the Roman provincial tetradrachm
in the 2nd century AD led to declining silver and increasing bronze content in these denominations of coins. Eventually, by the third quarter of the 2nd century AD, these coins were almost entirely bronze, with only a thin coating or even a wash of silver.
Alloy
An alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...
of a precious metal
Precious metal
A precious metal is a rare, naturally occurring metallic chemical element of high economic value.Chemically, the precious metals are less reactive than most elements, have high lustre, are softer or more ductile, and have higher melting points than other metals...
(most commonly silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
, but also mercury
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...
) with a majority base metal content (such as copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
). It is used chiefly for making coin
Coin
A coin is a piece of hard material that is standardized in weight, is produced in large quantities in order to facilitate trade, and primarily can be used as a legal tender token for commerce in the designated country, region, or territory....
s, medal
Medal
A medal, or medallion, is generally a circular object that has been sculpted, molded, cast, struck, stamped, or some way rendered with an insignia, portrait, or other artistic rendering. A medal may be awarded to a person or organization as a form of recognition for athletic, military, scientific,...
s, and token coin
Token coin
In the study of numismatics, tokens are coin-like objects used instead of coins. The field of tokens is part of exonumia. Tokens are used in place of coins and either have a denomination shown or implied by size, color or shape...
s.
The word comes from the French
French language
French is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...
bille.
The use of billon coins dates from ancient Greece
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
and continued through the Middle Ages
Middle Ages
The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...
. During the 6th and 5th centuries BC, some cities on Lesbos Island
Lesbos Island
Lesbos is a Greek island located in the northeastern Aegean Sea. It has an area of with 320 kilometres of coastline, making it the third largest Greek island. It is separated from Turkey by the narrow Mytilini Strait....
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.
Billon coins are perhaps best known from the Roman Empire
Roman Empire
The Roman Empire was the post-Republican period of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean....
, where progressive debasement
Debasement
Debasement is the practice of lowering the value of currency. It is particularly used in connection with commodity money such as gold or silver coins...
s of the Roman denarius
Denarius
In the Roman currency system, the denarius was a small silver coin first minted in 211 BC. It was the most common coin produced for circulation but was slowly debased until its replacement by the antoninianus...
and the Roman provincial tetradrachm
Tetradrachm
The tetradrachm was an Ancient Greek silver coin equivalent to four drachmae. It was in wide circulation from 510 to 38 BC.-History:Many surviving tetradrachms were minted by the polis of Athens from around the middle of the 5th century BC onwards; the popular coin was widely used in transactions...
in the 2nd century AD led to declining silver and increasing bronze content in these denominations of coins. Eventually, by the third quarter of the 2nd century AD, these coins were almost entirely bronze, with only a thin coating or even a wash of silver.
See also
- MetalMetalA metal , is an element, compound, or alloy that is a good conductor of both electricity and heat. Metals are usually malleable and shiny, that is they reflect most of incident light...
- Bullion
- List of alloys
- AntoninianusAntoninianusThe antoninianus was a coin used during the Roman Empire thought to have been valued at 2 denarii. It was initially silver, but was slowly debased to bronze. The coin was introduced by Caracalla in early 215 and was a silver coin similar to the denarius except that it was slightly larger and...
- ShakudōShakudoShakudō is a billon of gold and copper , mostly designed for its dark blue-purple patina. It was historically used in Japan to decorate katana fittings such as tsuba and kozuka...
- Swiss franc