Amethyst
Amethyst stimulates the third eye and all six “sensory gifts”; clairvoyance, clairaudience, claircognizance, clairsentience, clairolfaction, and clairgustation. Amethyst is one of the best stones to use for dreaming. It helps keep away nightmares. Use amethyst for the transformation of challenging situations. Amethyst is one of the stones of Imbolc.
Affirmation: I pay attention to my intuition and dreams.
More information on amethyst here: Correspondence of Imbolc: Stones