Last week I shared a rare Vespasian Concordia As in my 'Coining ritual' thread. https://www.cointalk.com/threads/a-coining-ritual.351945/ The type is fairly rare on the As and is much more commonly seen on the dupondius. I realised soon after acquiring the piece I did not have an example of the dupondius Concordia. That oversight is now rectified. Vespasian Æ Dupondius, 13.83g Rome mint, 71 AD Obv: IMP CAES VESPASIAN AVG COS III; Head of Vespasian, radiate, r. Rev: CONCORDIA AVGVSTI; S C in exergue; Concordia std. l., with patera and cornucopiae RIC 266 (C). BMC 589. BNC 565. Acquired from Romae Aeternae Numismatics, December 2019. A very common Concordia dupondius struck for Vespasian during the great bronze issue of 71. This type comes in two variants: one with an altar and one without. Both have the same frequency rating of 'common'. Mattingly in BMCRE speculated the type 'stands for harmony in the imperial house'. Do you have any types that are rare on one denomination but common on another?
The denarius is common: Julia Mamaea, AD 222-235. Roman AR denarius, 2.65 g, 20.5 mm, 1 h. Rome, issue 9A, AD 228. Obv: IVLIA MAMAEA AVG, diademed and draped bust, right. Rev: FELICITAS PVBLICA, Felicitas standing front, head left, legs crossed, holding caduceus transversely to left, and resting left arm on low column. Refs: RIC 335; BMCRE 483-85; Cohen 17; RCV 8209; CRE 502. The sestertius is common: Julia Mamaea, AD 222-235. Roman orichalcum sestertius, 19.91 g, 29.2 mm, 12 h. Rome, issue 9A, AD 228. Obv: IVLIA MAMAEA AVG, diademed and draped bust, right. Rev: FELICITAS PVBLICA S C, Felicitas standing front, head left, legs crossed, holding caduceus transversely to left, and resting left arm on low column. Refs: RIC 676; BMCRE 487-92; Cohen 21; RCV 8228. The dupondius is scarce: Julia Mamaea, AD 222-235. Roman orichalcum dupondius, 10.10 g, 24.3 mm, 12 h. Rome, issue 9A, AD 228. Obv: IVLIA MAMAEA AVGVSTA, diademed and draped bust, right, on crescent. Rev: FELICITAS PVBLICA S C, Felicitas standing front, head left, legs crossed, holding caduceus transversely to left, and resting left arm on low column, like she's Joe Cool or something. Refs: RIC 678; BMCRE 493-94; Cohen 23; RCV 8238. The as is scarce, too: Julia Mamaea, AD 222-235. Roman Æ as, 11.45 g, 26.4 mm, 1 h. Rome, issue 9A, AD 228. Obv: IVLIA MAMAEA AVG, diademed and draped bust, right. Rev: FELICITAS PVBLICA S C, Felicitas standing front, head left, legs crossed, holding caduceus transversely to left, and resting left arm on low column. Refs: RIC 677; BMCRE 495; Cohen 22; RCV 8243.
I believe that is the point of this post. The type is nothing but common but it is not evenly distributed among the denominations. We do not know why but someone could analyze the hoard data and die links possibly to determine if the coins were made in varying numbers or if it happened that one huge hoard made a rare coin originally appear common. It is not unreasonable for every known example of an ancient coin to have come from one find and we never know when someone will find a pot full that doubles the number known. Some collectors see no difference and group all coins of one person as KINDA the same. Others pay attention to details so small that most people do not notice them. I am not a Mamaea collector and only have three of her coins in my general collection. This type is not one. Whether that qualifies as KINDA one of these depends on your definitions. Correct answer!
Lovely coin again, @David Atherton. Unfortunately that's all I can add, however: I also don't have a type that is rare with one denomination, and common with another.
