Watch List notes:

Abbasid, al-Ma'mun, Dirham, Madinat Arran 213h, citing Khalid b. Yazid, al-a'z in lower reverse field, 2.56g (Vardanyan -; Lowick -; A 223.8). Cleaned, otherwise very fine and extremely rare, believed to be an unpublished variety for this date.
This variety is recorded by Vardanyan (no. 171) for 212h.

Estimate: £400-500