These are a few general rules to make sure that they last for generations, still looking like the day you bought them. Rings in particular tend to collect dust and soap behind the stone, particularly if you wear them all the time. To clean transparent crystalline gemstones, simply soak them in water with a touch of gentle soap. If necessary, use a soft toothbrush to scrub behind the stone. Even the hardest gemstone variety can be vulnerable to breakage if it has inclusions that weaken the crystal structure.
Diamonds are very hard but can shatter in two with a single well-placed blow.
Rubies and sapphires are the toughest gems but even they can chip if hit sharply. Think twice before putting gems in an ultrasonic cleaner. 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. Opaque gemstones like lapis lazuli, turquoise, and malachite require special care. Never use an ultrasonic cleaner and never use ammonia or any chemical solution.