Amethyst is the purple variety of the quartz mineral species. It’s the gem that’s most commonly associated with the color purple, even though there are other purple gems such as sapphire and tanzanite. Its purple color can be cool and bluish, or a reddish purple that’s sometimes referred to as “raspberry.”
It is also known as "Billaur". It is a stone which belongs to Saturn planet. A person who has Saturn debilitated in his horoscope should not wear Amethyst. Since the size of Mars is huge therefore Amethyst gives slow results (within 180 days). It is also called stone of spirituality, It is very effective if someone wants to come out of the habit of Alcohol. It is very good for meditation also.