collectors. The highest-grade sapphires or rubies are still orders of magnitude more expensive than amethyst. Handling and care The most suitable setting for gem amethyst is a prong or a bezel setting. The channel method must be used with caution. Amethyst has a good hardness, and handling it with proper care will prevent any damage to the stone. Amethyst is sensitive to strong heat and may lose or change its colour when exposed to prolonged heat or light. Polishing the stone or cleaning it by ultrasonic or steamer must be done with caution. See also Ametrine List of minerals Specimen Ridge References Kostov, R. I. 1992. Amethyst. A Geological-Mineralogical and Gemmological Essay. Union of Scientists in Bulgaria, Sofia, 249 p. (in Bulgarian with English abstract) Lieber, W. 1994. Amethyst. Geschichte, Eigenschaften, Fundorte. Christian Weise Verlag, München, 188 S. External links Quartz gemstones Provincial symbols of Ontario Trigonal minerals Minerals in space group 152 or 154