blue quartz

Rare natural blue variety of Quartz. It is caused by inclusions of blue minerals, especially Dumortierite. Most "Blue Quartz" is what is popularly known as "Aqua Aura", essentially clear Rock Crystal synthetically irradiated with gold to form a deep sky blue color. Blue Quartz may also refer to a dull grayish-blue Quartz in massive form with Crocidolite inclusions.