Formula: Enchant Gloves - Mining

Source
This item drops off of the following in Wetlands:
 * Dark Iron Dwarf
 * Dark Iron Demolitionist
 * Dark Iron Tunneler
 * Dark Iron Saboteur
 * Balgaras the Foul

These enemies can be found in Dun Modr and at the three camps along the northern mountain range, southwest of Dun Modr. Balgaras is in the eastmost camp along the mountains (not in Dun Modr).