ASIA MINOR. Uncertain. Marcus Aurelius, as Caesar, 139-161. Assarion (Bronze, 22 mm, 5.97 g, 6 h), 138-140/1. Μ ΑΥΡΗ OΥΗΡΟϹ ΚΑΙϹΑΡ ΔΗ ΕΞ Bare head of Marcus Aurelius to right. Rev. [ΦΑVϹΤΕΙΝ]Α [ϹΕ]Β[ΑϹΤΗ] Draped bust of Faustina I to right. RPC IV online 8072. Of the highest rarity, apparently the second example known. Rough surfaces, otherwise, about very fine.
The lack of ethnic makes an attribution of this enigmatic issue difficult, although it certainly is from Asia Minor. The ΔΗ ΕΞ in the obverse legend is to be expanded to ΔΗMAPXIKHΣ ΕΞOYΣIAΣ, 'with tribunician power', an unusual title in Greek that unfortunately does not provide any further help.