Gemstones are durable substances, still, they do need some care. Follow a few general rules and they’ll last for generations still looking brand new.
Keep your jewelry clean! Rings in particular tend to collect dirt behind the stone, especially if you wear them on a regular basis. You can clean transparent gemstones by simply soaking them in water with a touch of soap. Use a soft toothbrush to scrub the stone.
Even the hardest gemstones like Diamonds, Rubies and Sapphires can shatter with a single well-placed blow especially if they have inclusions, which weaken the crystal structure.
Think twice before putting gems in an ultrasonic cleaner. Diamonds, rubies and sapphires will be fine but many other gems may not be: when in doubt, leave it out. Diamonds, rubies and sapphires, and other single-crystal gems can be cleaned with a touch of ammonia in water to remove all films and add extra sparkle.
Never use an ultrasonic cleaner or ammonia for cleaning such opaque gemstones like lapis, turquoise, malachite or onyx. They should be wiped clean gently with a moist cloth. These gemstones can be porous and may absorb chemicals, even soap, which may build up inside the stone and discolor it.