Amethyst is basically purple in color. Green amethyst is prasiolite and should rightly be referred to by that name. Purple amethyst gems can be grouped into three main color shades, very light purple amethyst, medium purple amethyst and dark purple amethyst. The mosto popular color shade for amethyst stones is medium purple. Very pale amethyst stones are cheaper but could appear almost colorless so beware when choosing these gems. In the gemstone trade, pale to medium purple amethyst stones are referred to as Brazilian amethyst and stones with the more saturated purple color are called African amethyst gems. This reference might not always refer to their mining origin though. The www.directstones.com website has more information on this topic. http://www.directstones.com/february-birthstone-amethyst-ly-01.htm