Insightful Earthstorm Diamond

Insightful Earthstorm Diamond. 2% chance to restore 300 mana on spellcast.

The chance of the effect triggering may have been changed to 5% in patch 2.3

Source
Insightful Earthstorm Diamond is crafted by Jewelcrafters with a skill level of 365.

The design requires Friendly reputation with the Sha'tar.