|Mineral||variety of mineral Amethyst|
|Category||Crystals and geodes|
|Formula SiO2] AMETHYST|
|O||Oxygen||Other no metal||53.25%|
Amethyst is a variety of purple colored quartz made from silicon dioxide. It is a fine or even precious stone used in jewelry and as an ornamental stone. Its color, covering almost all shades of purple, from very light to very strong purple, is due to the iron inclusions it contains. It is a stone formerly rare but important deposits having been discovered at the beginning of the XXth century in Brazil and Uruguay, it is now a common stone.