I know this has been done before, but I just got these two Faustina I AEs and I was struck by how different they were, doing a better job than usual in showing the difference between an Imperial empress As and a Dupondius. For beginners: The difference between a dupondius and an as for an emperor is (usually) the radiate crown worn on the dupondius. The ladies are far more difficult to tell apart because the types are the same - the only way you can tell the difference is by size and/or color of the metal (copper for an as; brass (orichalcum) for the dupondius). Metal color is often obscured by patina, and the weights/diameters vary so much it is sometimes impossible to tell which is which. The two I just got are almost the same diameter, but thickness and color of the metal are very different - not always the case for these. So I thought I'd throw 'em out there. Please feel free to show some more, or correct my blathering. The As is on the left, the Dupondius on the right (note the dupondius has a slightly smaller diameter): Faustina I Æ As (c. 150-151 A.D. - Aet. types) Rome Mint DIVA FAVSTINA, draped bust right / AETERNITAS S C, Pietas standing left, raising right hand and holding box of perfumes in left hand (no altar). RIC 1162a; Cohen 44. (10.04 grams / 26 x 23 mm) Faustina I Æ Dupondius (c. 150-151 A.D. - Aet. types) Rome Mint DIVA FAVSTINA, draped bust right / AETERNI[TAS] S C, Juno standing left with raised right hand and holding scepter in left hand. RIC 1155; Cohen 29; Sear 4636 (13.86 grams / 25 mm)
You're right this is tough! For some heavily patinated specimens it's pretty much impossible to tell IMO. This Sabina was sold to me as an as, but given the brassy colour it must be a dupondius (11.24g, 28mm): Apparently the quality of the orichalcum deteriorated over time; maybe it was difficult even for contemporary Romans to tell the difference by colour (though of course the crown makes it easy for the male rulers). This issue of Severus Alexander, showing him as the "restorer of the coinage" (found only on quite a large issue of dupondii and possibly the occasional orichalcum sestertius), may reference an increase in the quality of the metal to something brassier. My example is too patinated to see any yellow: Compare to this rather coppery example from late in the reign of Elagabalus (not my coin): Although this dupondius of his mother Julia Soaemias is pretty brassy (also not my coin, sadly): Maybe it was only later in the reign of Elagabalus that quality suffered? I'd love to see a metal analysis to answer these questions.
Great information and cool coins! Here's a Faustina I As, Faustina II Sest and Lucilla Sest (I am utterly Dupondiusless): Faustina I Æ-As, 138/141, Rome; 10.29 G. Draped bust R.//Concordia sits L. With Patera, the L. Elbow supported on statue of Spes, under the throne cornucopia. BMC 1127; CoH. 149 var.; Ric1086 var. Faustina II (Minor) Sestertius, Rome, AD 161-175; AE, FAVSTINA - AVGVSTA, draped bust r., hair knotted behind with circle of pearls, Rv. HIL - A - RITAS, Hilaritasstanding l., holding palm branch and cornucopiae; in field, S - C. RIC 1642; C 112. LUCILLA Sestertius, RIC 1779, Vesta OBVERSE: LVCILLAE AVG ANTONINI AVG F, draped bust right REVERSE: VESTA, S-C, Vesta standing left, holding palladium and sacrificing with simpulum over lighted altar to left Struck at Rome, 161-161 AD 30.4 mm, 21.89g AD ex Bing CT
For the reigning emperor in the Antonine period, distinguishing between aes and dupondii is easy: the emperor is laureate in the case of the former and radiate in the case of the latter. For the empresses and princes, no formal difference of this kind is made and we must rely on which metal shows through the patina or on weight (inexact, as I will demonstrate). Typically, in the Antonine period, dupondii weigh about two grams more than aes. Here is a table from the introductory material in BMCRE4: However, there is a lot of variability and I wish the authors of BMCRE4 had listed the standard deviation and not just the mean weight in grains (converted to grams) and the number tested. This coin in my collection is clearly a dupondius, for example, but it weighs only 10.62 g: And this one -- also clearly a dupondius -- is massive, weighing in at 16.19 g: Here's an underweight as in my collection, weighing only 9.21 g: Wear may play a role, too, the more worn coins weighing less. The authors of BMCRE note a study by A.S. Hemmy reporting the results not in terms of arithmetic mean, but mode (the most frequently occurring weight), along with an estimated amount (in grains) to be added to account for wear, which was based upon a study of modern coins subjected to various degrees of circulation. These results are summarized here: Again, I note the weights and the correction for wear are given in grains in this table. To convert to grams, 1 g = 15.4324 grains. I wish the standard deviation had been included in the table. Going by weight CAN help distinguish between aes and dupondii, in that those weighing < 10.5 g are quite likely to be aes and those weighing > 12 g are quite likely to be dupondii, but in patinated specimens of intermediate weight, it can be impossible to tell which denomination it is.
It is also my impression -- not scientifically validated -- that dupondii tend to develop black patinas and aes tend to develop emerald green patinas. Anyone else notice this or know of a study that has examined this?
You guys have some really terrific examples. Thanks for sharing them. It does make you wonder if there wasn't a certain amount of monetary chaos with the as/dupondius similarities. Something akin to the UK double florin/crown situation of 1887.
