DIRHAM درهم
Greek . A silver coin, the shape of which resembled that of a date stone. During the caliphate of ‘Umar, it was changed into a circular form; and in the time of Zubair, it was impressed with the words Allah, “God,” barakah “blessing.” Hajjaj stamped upon it the chapter of the Qur’an called Ikhlas (cxii), and others say he imprinted it with his own name. Various accounts are given of their weights; some saying that they were of ten, or nine, or six, or five misqals; whilst others give the weights of twenty, twelve, and ten qirats asserting at the same time that ‘Umar had taken a dirham of each kind, and formed a coin of fourteen qirats, being the third part of the aggregate sum. (Blochmann’s Ain-I-Akbari, p 36.)
The dirham, although it is frequently mentioned in books of law, only occurs once in the Qur’an, Surah xii 20, “All they sold him (Joseph) for a mean price dirhams counted out, and they parted with him cheaply.” for a mean price, dirhams counted out, and they parted with him cheaply.”

Based on Hughes, Dictionary of Islam