Amethyst is the purple variety of quartz and the most valued member of the quartz family. It is found inside geodes and in alluvial deposits worldwide. When manganese is present in clear quartz amethyst is produced, while the amount of iron contained in the specimen accounts for the depth of purple. Its purple color made it a stone of royalty for many thousands of years.
Amethyst is usually purple but in a range of shades including deep purple, light lilac, lavender and mauve. Top quality amethyst is a deep medium purple with rose-colored flashes. Pale amethyst stones after irradiation and/or heat treatments turn the color green and is known as Green Amethyst, Prasiolite or Green Quartz.
Amethysts may be found all around the world with larger deposits in Brazil, Uruguay and Madagascar.