How to Identify the Aureus of Augustus

What This Coin Is

The aureus was Rome's principal gold coin, valued at 25 silver denarii. Augustus regularized its weight standard and design program as part of his broader reform of Roman coinage after becoming sole ruler.

Obverse Design

The obverse shows a bare or laureate head of Augustus facing right, surrounded by an abbreviated imperial title legend. The portrait style generally mirrors the denarius issues struck at the same mint during the same period.

Reverse Design

The aureus shares many reverse types with the contemporary denarius, including Gaius and Lucius Caesar standing with shields and spears, a Capricorn, a Victory on a globe, and types honoring Augustus's adopted heirs and other family members.

Size, Weight, and Metal

Struck in nearly pure gold, the aureus is noticeably denser and heavier than a silver denarius of similar diameter. Its nominal weight sits around 7.9 grams under the standard Augustus established, with a diameter of roughly 19-20mm.

Mint Marks and Attribution

As with the denarius, most surviving aurei trace to the Lugdunum mint and carry no explicit mint mark. Die style and portrait treatment, matched against companion denarius issues of the same type, are the main tools for attribution.

Telling It Apart From Similar Coins

The first check is color and weight: gold has a warm, buttery yellow luster and a noticeably higher density than silver. Be careful not to mistake a well-preserved gilt-silver fake, which is lighter and often shows silver at any wear point, for a genuine solid-gold piece.

Grading at a Glance

Gold does not tone or corrode, so genuine ancient aurei often look remarkably fresh even after two thousand years. Grade primarily by strike sharpness, centering, and handling marks such as scratches or edge nicks rather than by surface color changes.

Authenticity Red Flags

Any exposed base metal at a scratch, wear point, or edge nick indicates gold plating over a fake core. Check the weight precisely, since a genuine aureus should sit very close to the period standard, while modern reproductions are often noticeably light or heavy. Be suspicious of cast rather than struck examples, which typically show soft, rounded details and a visible casting seam.