|A Royal Imperial gold aureus of the emperor Allectus, on display at the Roman Baths Museum. This is a good example of a coin in excellent condition.|
As with modern coins, there were denominations of Roman coins, which were worth different amounts and made out of different materials. These are shown here in decreasing value:
Metal: Coin: Value:
Gold Aureus 25 denarii
Gold Quinarius 12 ½ denarii
Silver Denarius 16 asses
Silver Quinarius 8 asses
Orichalcum Sestertius 4 asses
Orichalcum Dupondius 2 asses
Copper As 4 quadrantes
Orichalcum Semis 2 quadrantes
Copper Quadrans ¼ as
The nature of the metal is also important for identification. The silver content of a denarius or quinarius can help with dating - the first silver coins were often 95% pure! This standard was dropped, raised, and then dropped again until in 270 it contained a mere 1% silver. The coins made from orichalcum are what we know today as brass, being made from a particular alloy of zinc and copper. This helped to distinguish similar coins through a difference in colour. The dupondius and as were about the same size, but could be told apart because orichalcum is very yellow in colour, and copper is obviously red.
Size, weight and thickness are three other factors that are very useful when identifying Roman coins. In general, the size of Roman coins decreased over time, from the hefty bronze examples of over 25mm across and more than 3mm in thickness, through to the tiny nondescript issues from the period between 260 and 402. This can provide an indication of the coin’s date at a glance, particularly when confronted by a large selection of unidentified coins.
Inscriptions and images are essential in identifying coins. Roman coins were decorated on both sides, usually with the emperor on the front (obverse). The reverse types are varied, but commonly show depictions of various deities, victories, architecture, animals, or representations of the emperor’s family. The front of the coin will generally bear an inscription showing the emperor’s titles and dignitaries, whereas the reverse is dependant on what is depicted, with the inscription being relevant to the goddess shown, for example. The reverse of the coin sometimes bears inscriptions with information about the coin itself. This includes the letters S.C., found on the backs of copper and orichalcum coins after 23 B.C. This stands for ‘Senatus Consulto’ to show that the coin has been issued by the Senate. When mint-marks appear, they are also usually imprinted on the reverse. These were introduced in order to control and standardise the activities of mints.
|When coins are very worn or damaged they can be impossible to identify. This coin shows the state in which the majority of coins are found, although this one is a particularly extreme example.|
Richard Reece & Simon James 1986. Identifying Roman Coins. London, Seaby Ltd.
David R. Sear 1974. Roman Coins and their Values 2nd edn. London, Seaby Ltd.
Zosha - Roman Baths Intern