Gemstones are ranked for their level of hardness using the Mohs scale. While this hardness refers only to how easily a gemstone can be scratched (not how resistant it is to knocks, for instance), it’s a good indicator as to how suitable a gemstone is to be worn on your hand, as they are more exposed to possible damage there.
Diamonds are the hardest gemstone, with a Mohs rating of 10. They can only be scratched by other diamonds. Sapphire stones and rubies are the second hardest gems, making them excellent choices for rings and particularly engagement rings, since these are worn every day.
Amethyst, aquamarine, peridot, rhodolite garnet, morganite, and tourmaline all have quite high levels of hardness, making them suitable for gemstone rings also.
Pearls are a ‘softer’ gem and so pearl rings should be worn with care to avoid them scratching against abrasive surfaces, or coming into contact with harsh chemicals.
All gemstone rings should be treated with care to keep them at their polished, sparkling best.