Aura crystals have, according to the book The Crystal Bible, pecial properties of their own. They are titanium coated, but in the process, other metals used to create the auras they inevitably have. I will include more information about aura crystals in a new information page. These bronze colored aura crystals are called Fire auras. They are larger than the other quart point aura crystals in the collection, and, in general, more sought after by collectors.