Watch List notes:

ABBASID: al-Ma 'mun, 810-833, AR 1/6 dirham (0.43g), Marw, AH202, A-223K, date after bism Allah al-rahman al-rahim in obverse margin, mint name below the reverse field, professionally cleaned, pierced, appears to be unique, the first known example of this fractional denomination, VF, RRR.

Estimate: 200-260 USD