Discovering the Mystique of Green Amethyst Not only historical significance, green amethyst also contains several physical properties that include its color which varies according to the gemstone and is majorly found in Brazil and the USA. The chemical composition of prasiolite is SiO2(silicon dioxide), and it can be cut into several shapes which include round, oval, pear, square, emerald etc. The specific gravity of green amethyst is 3.49 to 3.57 and refractive index is 1.543 to 1.553, and the most important physical properties of green amethyst is its hardness which is 7 on the Mohs scale which makes it more durable and an excellent gemstone in the world of gemstone jewelry.