Our crystal of the month, amethyst, was traditionally worn to prevent drunkenness. It still has a sobering effect and supports sobriety, overcoming addictions and blockages of all kinds.
Amethyst is a very spiritual crystal which opens intuition and enhances psychic gifts, particularly when placed on the third eye.
It is a good remedy for insomnia caused by an overactive mind. Be sure that you don't have any amethyst in the bedroom however, as it will cause some whacky dreams and leave you feeling unrested in the morning. Hold (or wear) this crystal for around 20 minutes whilst watching TV or reading before you go to bed.