Helium Filaments are materials that are used to upgrade legendary and exotic weapons and armor. Helium Filaments can be harvested from Helium Coils, which appear randomly in some areas on the Moon. Helium Filaments may also be awarded to players for opening loot chests on the Moon, completing Daily Heroic Story Missions, turning in Patrol or Queen's Wrath bounties, or opening Judgment's Grant packages. They can be purchased from the Vanguard Quartermaster for Vanguard Marks or the Crucible Quartermaster for Crucible Marks at a rate of 10 Marks for 20 Helium Filaments.
Once obtained, Helium Filaments are stored in a player's inventory. 200 Helium Filaments can be stored in a single stack, after which point a new stack is started.