Billon (alloy)

[1] The use of billon coins dates from ancient Greece and continued through the Middle Ages.

During the sixth and fifth centuries BC, 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.

Eventually, by the third quarter of the third century AD, these coins were almost entirely bronze, with only a thin coating or even a wash of silver.

These coins are easily identifiable by their color and by the presence of a large mintmark on top of the dome of Monticello.