Here is a rare coin that was sold by Gert Boersema on Vcoins, his description below-
Constantinopolis. AE Medaillon (17mm, 1.85g) Constantinopolis c. AD 330
CONSTANTINOPOLIS; Pearl-diademed bust of Constantinopolis right
Pax standing left, holding transverse sceptre and olive branch, P and R on either side
RIC VIII 106 (attributed to the Rome mint, dated AD 348), this mint and date after Simon Bendall, “Some comments on the anonymous silver coinage of the 4th to 6th centuries†in RN 158 (2002), 139-159 and Lars Ramskold, “Coins and medaillons for the inauguration of Constantinopolisâ€, Nis & Byzantimum IX, 125-158; Very fine