Watch List notes:

ABBASID OF YEMEN: al-Ma 'mun, 813-833, AR ¼ dirham (0.73g), San 'a, AH210, A-1050R, Zeno-36999 (same dies), with the denomination expressed as rub ' below the reverse field, choice VF-EF, RRR. In AH208, al-Ma 'mun 's authorities replaced the light weight Yemeni dinar, struck since AH171, with the traditional full dirham, but struck coins only in the half, third, and quarter, with the actual denomination indicated for the third and quarter below the reverse field, "thulth" for the third and "rub '" for the quarter. These were struck only in AH208-210.

Estimate: 300-400 USD