Amethyst aura is natural amethyst that has been bonded with silver that produces a beautiful opalescent sheen to the amethyst.  It has all of the regular properties of amethyst in addition to being a little more uplifting and peaceful.
Amethyst is said to help with emotional balance, stress relief, and relaxation.
It can also be used for cleansing and charging other crystals by placing them onto the piece.