Darkstone of Terokk
From WoWWiki
The Darkstone of Terokk is located in Veil Skith of Terokkar Forest. [30.8, 42]
Objective of
Needs to be purified for the quest 
[64] Veil Skith: Darkstone of Terokk.
Trivia
The darkstone is a reference to the dark crystal in the film The Dark Crystal.
