ISLAMIC, 'Abbasid Caliphate. temp. Al-Ma'mun, AH 193-218 / AD 809-833. Dirham (Silver, 24 mm, 2.99 g, 4 h), citing al-Fadl, the vizier of the caliph al-Ma'mun as Dhu'l Riyasatayn (holder of the two ministries), Madinat al-Salam, AH 198 = AH 813/4. SICA III, 1731. Nicely toned. Good very fine.
From a Swiss collection of Umayyad and Abbasid coins, assembled in the 1970-1980s (with original flip with S. Album's description).