When we think of ancient gold coinage, there is the tendency to think in terms of contemporary coins. This is not the case, however. The two coinages are very different.
The gold solidus of Constantine, which retained its value and served as a monetary standard for more than a thousand years, was unlike an American coin, for example, that represented an ounce of the precious metal. The fourth century solidus consisted of one seventy-second of a pound of gold.
Historian Peter Spufford notes that the solidus was “a little larger than a modern American dime or English penny, although, being gold, it was much heavier than either” (Peter Spufford, Money and its Use in Medieval Europe, Cambridge University Press, Cambridge, 1988, p. 7).