Watch List notes:

ISLAMIC, Ghaznavid, Mahmud b.Sebuktegin, (388-421 A.H.; A.D. 998-1030), gold dinar, (3.54 g), Herat mint, year 418 (A.D. 1027-1028), (A.1607). Very fine, off centred and weak in places.

Ex Steve Album, with his descriptive packet.
Coins were minted in Herat from 389-421. The gold alloy was generally rather good until about 408 and became increasingly pale thereafter.