The Rise of Peridot Rings: Why Is It Stealing Hearts Everywhere Peridot Rings is considered to be a semi-precious olivine or chrysolite mineral gemstone. On the Mohs Scale of Mineral Hardness, this stone clocks between 6.5 and 7. The specialty of peridot gemstone is it is one of the only semi-precious gemstones that is not formed in Earth’s crust, rather, it is formed inside the molten rock of Earth’s upper mantle.