Amethyst is the most popular variety of quartz crystals that is considered the most powerful and protective stone. It is a semiprecious violet stone that is often used in jewelry and for healing purposes. It has been sought after throughout the ages for its stunning colors and ability to stimulate the mind and emotions. It associated with cleansing, protection and inspiration. It is known to enhance intuition, spirituality and mediation. Extremely protective. Calms the mind and spirit. Protects from nightmares and insomnia.