Watch List notes:

Abbasid, al-Ma'mun (194-218h), Dirham, Madinat Isbahan 203h, citing the heir al-Rida and the vizier Dhu'l-Riyasatayn, 2.75g (Lowick 1535 var.; A 224; W 391). Peripheral hornsilver, otherwise good very fine, rare.