Infused Saronite Bar

Source
Stacks of Infused Saronite Bars can be found littering the ground in the Pit of Saron of the Frozen Halls in Icecrown Citadel. The Infused variety have a green miasma steaming off of them. Other stacks of Saronite Bars do not have this glow.

The use of five bars are required for the quest Reforging The Sword, along with a drop from Forgemaster Garfrost, The Forgemaster's Hammer, to reforge the Remnants of Quel'Delar into the Reforged Quel'Delar.