ABBASID: al-Mahdi, 775-785, AR dirham (2.93g), al-Yamama, AH165, A-215.1, inscribed hajar below the reverse field, heavily cleaned, VF, R. Al-Yamama was the first mint in Arabia to strike silver coins, located near the modern city of Riyadh, with its administrative capital at the town of Hajar. It operated AH165-170, after which the production of silver coinage was moved to San a in Yemen, starting in 171, albeit at a local reduced weight standard.
