Amethyst is the purple variety of quartz, and Brazilian amethyst tends to be lighter in tone than African material, but with superb clarity. The colour is usually a mid-purple and because of the clarity, the lustre is excellent. It's affordable too, even in large sizes as the price does not rise exponentially with carat weight. Once one of the most rare and valuable gemstones, amethyst is now plentiful but remains enduringly popular. In Brazil the amethysts form in hollow, crystal lined geodes so large you can stand in them*.