Abbasid Caliphate. al-Ma'mun. 194-218/810-833. Æ fals (19.1 mm, 2.06 g, 12 h). Samarqand, AH 205. Citing the regional governor Ghassan b. 'Abbad, fl. 820/821. VF, nice even strike. Very rare. Purely Samanid copper coins were struck later in this year, citing the first Samanid ruler, Nuh I b. Asad.