Korin is the currency of Aren'ekel.
It is similar in size to a stone button, though has edges gilded with Iron, and in it's centre is Aren's symbol enstamped with Lapiz Lazuli.
Korin is the only currency allowed to be used for trade within the city of Aren, and can be exchanged for Crimin at the Aren Commerce Commission building.
The exchange rate is 10 Crimin to the Korin when exchanging to Korin from Crimin. Or 2 Korin to 17 Crimin when converting Korin into Crimin. The discrepancy in exchange rates depending on which currency you are converting to is due to taxes imposed by the government of Aren.