An Adamant helm (h3) is a helmet obtained from the Level 2 Treasure Trails, or bought from other players. It cannot be made using the Smithing skill.
It has stats identical to that of an adamant full helm, the only differences being that the helm is more expensive, has a different appearance, cannot be smithed, and can only be obtained through Treasure Trails or through trading with another player. There are also three other heraldic helms made of adamant, each having a different heraldic design. There are also heraldic helms in rune and black with the same designs.