Amethyst: Amethyst is a violet variety of quartz. The lovely purple amethyst is one of the most popular gemstones for jewelry and the one most associated with crystal healing. It is used for protection, intuition, spirituality, and helping to change bad habits or addictions. Amethyst jewelry and other uses date back to Neolithic times 25,000 years ago. Amethyst is the birthstone for February. It also has meaning to the astrological signs Pisces, Aries, Aquarius, and Sagittarius. Amethyst crystal is found in Russia, India, Brazil, US, Canada, Australia, and South Korea.