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 Crocidoliteinclusions.
