Relic Iron is a material that is used to upgrade weapons and armor. Relic Iron can be harvested from Relic Shards, which appear randomly in some areas on Mars. Relic Iron may also be awarded to players for opening loot chests on Mars, turning in Patrol or Queen's Wrath bounties, or opening Judgment's Grant packages. They can be purchased from the Vanguard Quartermaster for Legendary Marks at a rate of 10 Marks for 20 Relic Iron.
Once obtained, Relic Iron is stored in a player's inventory. 200 Relic Iron can be stored in a single stack, after which point a new stack is started.