http://www.mindat.org/min-198.html

http://www.galleries.com/minerals/gemstone/amethyst/amethyst.htm

http://www.bernardine.com/gemstones/amethyst.htm

http://www.crystalsgems.com/amethyst/amethyst-at-a-glance/

http://www.galleries.com/minerals/gemstone/amethyst/amethyst.htm

http://geology.about.com/library/bl/images/blamethyst.htm

http://www.crystalcavern.com/amethyst.html

http://www.jewelrysupplier.com/2_amethyst/amethyst_healing.htm

http://www.jewelrysupplier.com/2_amethyst/amethyst_dreaming.htm

http://en.wikipedia.org/wiki/Amethyst_(color)

http://www.factmonster.com/ce6/sci/A0803720.html