Watch List notes:

ABBASID: al-Mahdi, 775-785, AR dirham (2.70g), al-Yamama, AH165, A-215.1, inscribed hajar below the reverse field, rare date; cleaned, EF, 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 from 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.

Estimate: 300-400 USD