Here's another read from Good Housekeeping Magazine this time it's how to brighten your gold jewelries and gems and stones attached to it.
Gold chains, pendants, gems can lose its glistening appearance through everyday wear. To bring up their bright image give your gold jewelries a bubble bath by pouring a few drops of mild dish soap into a small bowl of sodium-free seltzer water. Put the jewelry into a small strainer, and place it in the bowl to soak for about five minutes. Brush crevices using soft toothbrush. Return jewelry to strainer and rinse it under running water then dry with a cloth.
For costume jewelry, especially if stones are glued rather than set, dab a cloth into the bubbly solution and gently wipe smudges, then rinse with cloth dampened in plain water. Pat dry and lay the pieces upside down so that moisture won't soak into the setting,
That's it. Hope this short tip will help you too.