The sentimental value of most fine jewelry or precious gems can vastly increase their worth to the owner, making the care of both old and new heirlooms a doubly important task.
The American Gem Society, a national non-profit organization of retail jewelers, recommends professional cleaning for your fine jewelry, or this home-made solution:1 tablespoon liquid detergent (such as Mr. Clean or equivalent); 1 tablespoon pharmaceutical ammonia (sometimes called stronger ammonia water, available at pharmacies); 1/2 cup warm water
Dip the jewelry in this solution and let it soak for five minutes. Then gently brush clean with a very soft toothbrush. After cleaning, jewelry should be dried on a lint-free towel.
Some notes of caution: Be sure to use pharmaceutical ammonia; household ammonia leaves a film. Do NOT use the solution on porous gemstones that might lose their color, such as lapis lazuli, coral, turquoise, opal and pearls.