Various gemstones are thought to have specific healing powers. Amethyst is the February birthstone (in green or purple). It is said to be the third eye chakra stone and is thought to aid sleep and help stomach disorders. It's also reputed to be good for addictions, easing arthritis, enhancing intuition and left brain imbalances. Because it stimulates the third eye it is considered an aid for psychic insight, spiritual opening and internal surrender.
Here's some beautiful jewelry featuring amethyst gems.