Here’s an interesting recent post by my friend Larry Hurtado on Christian graffiti on pagan coins…
I was contacted a couple of weeks ago now to comment on a Roman-era coin recently acquired that exhibited marks indicative of Christian graffiti. This introduced me to something that I hadn’t known about before. The coin in question is a large (ca. 42 mm) copper-alloy piece minted in the reign of Elagabalus (Marcus Aurelius Antoninus, 188-217 CE). On the side showing a profile portrait of Elagabalus there is a chi-rho added by means of indendations that are then joined. There is also what appear to be a nomen sacrum form of the Greek name “Jesus,” the Greek letters IHC made in the same way.
For comparison, I was directed to a similar coin held in the British Museum, which can be viewed online here. This one too is large (ca. 40 mm) and copper-alloy, and was minted in the early 3rd century CE. It shows the portrait of Emperor Caracalla, and on it, too, someone has etched a chi-rho to the left of the Emperor, and the letters alpha and omega to the right. In addition, on the rim is the Latin word PAX.
Such large (but low-value) coins were often used (long after they ceased to be minted) as grave-markers in underground burial chambers. It appears likely that both the British Museum coin and the one about which I was contacted were used for this purpose, the Christian graffiti added to “Christianize” the marker. So, these items put us in direct touch with the burial practices and piety of some ancient Christians, probably in the 4th century or perhaps the late 3rd century CE.
For more information on coins relating to the biblical texts, ancient Judaism and early Christianity, I commend the splendid book by Richard Abdy and Amerlia Dowler, Coins and the Bible (London: Spink, 2013), which was published in conjunction with an exhibition by the same name held in the British Museum May-October 2013.