Watch List notes:

ISLAMIC, 'Abbasid Caliphate. temp. Al-Mahdi, AH 158-169 / AD 775-785. Dirham (Silver, 25 mm, 2.82 g, 4 h), citing al-Mahdi as 'al-Khalifa', Madinat al-Salam, AH 161 = AD 777/8. SICA III, 1622. Minor marks and with light deposits, otherwise, about extremely fine.