Black Dragon Soul Gem

The is a consumable item from Temple of Tiamat.

Once used, cleanses the acid debuff from the black Tiamat head.

Acquisition
drops from one of the 5 summoners in Phase 1 of Temple of Tiamat: Defeat the Summoners.

Cooldown
Base cooldown is 120s, but can be lowered on higher tiers of contributions made by Rewards for the Hoard repeatable quest.