Amethyst Sterling Silver Ring Deep purple facetted amethyst gemstone set in a sterling silver ring. Historically, amethyst has been associated with protection from higher powers since ancient times. Christianity onwards, the theme of purity of spirit was associated to this gemstone. Amethyst is one of the accepted modern birthstones for February or the zodiac sign of Aquarius. In modern times, amethyst has been associated with the themes of spirituality, elevation, and alignment with one’s aspirations.