Powdered Iron
Powdered Iron is an imbuing ingredient needed to imbue durability property onto items. Some creatures in the Cavern of the Discarded may also carry it as a loot item.
It also can be crafted by blacksmiths with: at least 110.0 Blacksmithing skill; a Smith's Hammer or Tongs; 1 White Pearl; and 20 Ingots.