Watch List notes:

Arab-Sasanian. 'Umar b. 'Ubayd Allah. 67-70/686-689. AR drachm (31 mm, 3.78 g, 10 h). Eastern Sistan series. SK (Sijistan) or perhaps Zaranj, A.H. 70. Crowned Sasanian-style bust copying Khusru II; with bism allah and trefoil of pellets, rabbi and trefoil of pellets, in second and third quarters of margin respectively / Sasanian-style fire altar with attendants. SICA 1 -; Sears class II; cf. Album 76. Rare. Well centered and struck. Nearly extremely fine. 

In years past, the Eastern Sistan series - all with the mint signature SK often crudely engraved and dates frequently illegible - was marketed as Zabulistan, the region around the modern city of Ghazni in Afghanistan. However, recent evidence points to a minting location somewhere between Zabulistan and and central Sijistan, or perhaps as Sears suggests, a mint located in Zaranj, the capital of the entire Sijistan province. Sears concludes that these Sasanian-style drachms were sometimes struck concurrently with Abbasid dirhams, the drachms for eastern use and the dirhams for payment to the caliphal treasury and general circulation in the entire caliphate. Indeed, Album records evidence which supports Sears' attribution: Album A80 contains the inscription duriba bi-zaranj ("struck at Zaranj").