Opal symbolizes confidence, clarity, and calmness and is said to promote faith in oneself and hope for the future. Wear an opal pendant to capture these qualities. Yellow gold brings out the bronze and golden colors inside a smoky quartz pendant. White gold will highlight the brown and grey tones of the gem. Either way, you can't go wrong. A perfect stone for nighttime wear, a black onyx pendant looks elegant and stylish in white or yellow gold.