Amethyst is a popular purple-colored variety of quartz that contains manganese. It is the manganese that produces Amethyst's purple color, the iron content in the stone determines the relative darkness of the purple.
One of the most popular metaphysical stones, Amethyst is very powerful and protective. Known as the "stone of sobriety," Amethyst connects the physical plane with higher realm, making it a good choice when working with the Third Eye Chakra. Amethyst provides a wonderful peaceful energy for meditations. Amethyst opens and activates the Crown Chakra as well, allowing easier access to the divine.
Do bear that Reiki and crystal healing is believed to balance energy for the purpose of pain management, stress reduction and relaxation. These treatments should not be treated as a substitute for medical or psychological care. Crystals are powerful and should be treated with respect.