Uncia (coin)

The uncia was a Roman currency worth one twelfth of an as.

Republican coin

By derivation, it was also the name of a bronze coin valued at of an as made during the Roman Republic. The uncia started as a Roman-Oscan weight of 22.75 grams for a 273-gram pound, with Attic weight issues of about 27 grams under the libral standard for a 327 gram pound and was produced occasionally towards the beginning of Roman cast bronze coinage. Obverse types of the uncia include a knucklebone, a barleycorn, and the helmeted bust of Roma.

Empire coin

In imperial times the uncia was briefly revived under Trajan and Hadrian. This coin was about in diameter and weighed about. It featured the bust of the emperor on the obverse with no inscription and "SC" in a wreath on the reverse. If this issue belonged to the imperial system, meaning it was not a provincial piece, it would be an uncia. This issue may have been made only for circulation in the East.