From WoWWiki

Relic refers to a type of equipment worn in the relic equipment slot by druids, paladins and shamans and ranged equipment slot by warlocks. Relics were added in Patch 1.10.

There are four different types of relics, each specific to a class:

• Idols used by Druids.
• Librams used by Paladins.
• Totems used by Shamans.
• Spellstones and Firestones used by Warlocks.

v • d • e Equipment and weapons Armor Cloth · Leather · Mail · Plate – Cloak · Necklace · Ring · Trinket · Shield Armor sets Druid · Hunter · Mage · Paladin · Priest · Rogue · Shaman · Warlock · Warrior Melee weapons Axe · Dagger · Fist · Mace · Polearm · Staff · Sword – One-handed · Two-handed · Main hand · Off hand · Dual wield Ranged weapons Bow · Crossbow · Gun · Thrown · Wand – Arrow (Quiver) · Bullet (Ammo Pouch) Relics Idol · Libram · Totem · Spellstone/Firestone