Thread by @MPilekic

A few remarks on the assumed discovery of the "new" Emperor/Usurper #Sponsianus from a numismatic point of view: 🧵1/15

Image: #PLOSONE: Authenticating coins of the ‘Roman emperor’ #Sponsian dx.plos.org/10.1371/journa… CC-BY 4.0
#numismatics

At the first place, the new study outlines very well the history of research around the Sponsianus coins. What is new is the emphasis on circulating marks (wear) and especially the study of superficial deposits on the coins. The latter is a really exciting approach. 2/15

I try in the following to present only some points briefly and comprehensibly, which from a (personal) numismatic point of view have received too little weighting or too much. Completeness is not possible on Twitter. 3/15

That the coins are considered forgeries of the 18th century has good reasons and was not simply repeated over decades without further examination. 4/15

One important indication is that the coins were cast and not minted as they were supposed to be. I am not aware of any emperor/usurper who had his official coins cast. Modern forgeries have always been gladly cast. But ... 5/15

But applies to ancient forgeries as well, which means it could still be an ancient forgery, of course. Either way, however, it would not be an official coinage of a Roman Emperor/Usurper.
Stylistically, the coins of Sponsianus are a far step from the coins of the 3rd century.6/15

They still correspond most closely to so-called imitations, which were produced in antiquity but outside the Roman Empire and are found in the area of today's Ukraine - a completely different and complex issue. But ... 7/15

But again, especially because even these imitations were usually not cast, they are not coherent. Furthermore, the shape of the letters, the completely unusual titulature also rather speak for a modern forgery. 8/15

In this case, not even for an ancient forgery, since one would certainly rather have kept to something that was already there. For example, the reverse of the coin, whose prototype is the reverse of a Roman silver coin, but dated almost 400 years earlier. 9/15

It is possible that the prototype was known at the time, but just quite and more likely that this silver coin came from a modern collection and was used to make a casting mould. A return to this motif makes no sense at all to me in the 3rd century. 10/15

Now to the central points of the study, the circulation and deposition marks:
Interpreting circulation marks has always been difficult, not only because they too can be faked. Even because a coin shows few wear marks, it does not mean that it would hardly have circulated. 11/15

The fact that the wear or circulation marks also cannot be used conclusively as proof of authenticity is, however, also admitted in the study, since, among other things, published studies on the subject are lacking. 12/15

The topic of the superficial deposits on the coins is indeed the most interesting, but for me also methodically the least comprehensible. The deposits on the coins to be examined are studied and compared with deposits from genuine coinage. 13/15

Especially with cabinet coins, we often hardly know the object history or biography. Even if the deposits are similar, that tells us little about how long these pieces may have been in the ground somewhere, or even how often. 14/15

Decades or even more could pass before a coin ended up in a museum from the time it was found.
For me, therefore, the question is whether it is a modern forgery or an ancient imitation. In either case, the existence of Sponsianus would not be proven. 15/15