Amazonite is alkali feldspar mineral, a potassium aluminium silicate with a hardness of 6 to 6.5. Its crystal system is triclinic and prismatic. Its colour is green or blue-green. Its name derives from the Amazon River in Brazil, where there are important Amazonite deposits Amazonite is also found in Colorado, India, Madagascar, Namibia and Russia. Amazonite jewellery was produced as long as four thousand years ago. It was used in India, Egypt, Sudan and Mesopotamia. Amazonite was also used in jewellery worn in pre-Columbian South and Central America. In ancient Egypt, Amazonite was a popular amulet stone, and the Assyrians associated Amazonite with the god Belus.