Amethyst

Amethyst is a purple variety of quartz and owes its violet color to irradiation, iron impurities, and the presence of trace elements, which result in complex crystal lattice substitutions. The hardness of amethyst is the same as quartz, 7. The ancient Greeks wore amethyst and carved drinking vessels from it in the belief that it would prevent intoxication.  Amethyst is the power stone of the Crown Chakra and is thought to transform negative energy into positive energy, open intuition, clear and liberate; help with grief and sadness and bring inner peace; awaken and stimulate awareness.