Rune of Clangeddin is a component needed to upgrade the Runehammer. This item appears in Baldur's Gate II: Throne of Bhaal and Baldur's Gate II: Enhanced Edition.
It can be found in the house behind the woodcutter outside of Sendai's Enclave.
|“||The dwarven clan of Clangeddin were reknowned for their enchanted forges, and the magical darksteel hammers which came from them. There is a powerful aura of magic on this rune etched stone, though by itself the stone has no obvious use.||”|