Star of Elune

Star of Elune is a gem that is used in both Jewelcrafting and in Engineering, the gems fit. They are named after the goddess Elune.

Source
This gem is mined from Fel Iron, Adamantite, Rich Adamantite and Khorium deposits. It is also a world drop.

As an ingredient
Star of Elune is used in the following recipes:

Jewelcrafting

 * Circlet of Arcane Might
 * Gems:

Engineering

 * Stabilized Eternium Scope
 * Destruction Holo-Gogs
 * Powerheal 4000 Lens