Watch List notes:

ABBASID: al-Ma'mun, 810-833, AR dirham (2.77g), Madinat Arran, AH214, A-223.4, Vardanyan-, citing the officials Khalid b. Yahya and Ibrahim b. Attab al-Ma'muni (sic), unpublished date (Vardanyan knew of 213 and 215, but not 214), EF, RR.

Estimate: 200-300 USD