Citrine opal aura or citrine aura is double treated. Each piece started as amethyst, was heat treated to give the golden chicken tender color and then placed in a vapor chamber to give the rainbow iridescent coating. Because of the double treatment some of them are fragile so aren’t meant to work with metaphysically but are great to display. Just like how amethyst has its different hues, these do as well. The darker ones are from Uruguay and the lighter ones Brazil.