Améthyste polie no.703Amethyst no. 703 Variety of quartz whose purple tint is due to iron. It has been used as a gemstone since ancient times. Amethysts come mainly from Brazil, and Uruguay and Mexico. The purple color can be different in intensity depending on the origin or the quality of the stone. Just like Quartz Crystal its hardness is 7 on the Mohs scale. When the degree of heat exceeds 500 degrees c. the color of the amethyst turns to yellow to get closer to citrine