The strange black substance, scattered around Icewind Dale, is of great interest to the Duergar of Clan Sunblight. Large "deposits" of the material, jutting out of the ground are suddenly hotbeds of Duergar activity, and they seem to be harvesting/mining the material.

artist's rendition:

Find out what they're up to, why they need so much Chardalyn, and disrupt their mining operation.