A pair of sapphire earrings set in yellow or white gold is a classic, and is always appropriate. Choose from genuine sapphire, or the more affordable lab-created gem. A pair of black onyx earrings are an affordable and elegant gift. Always appropriate and always in style, black onyx should be in every jewelry box. Tourmaline is known as the gem of love and commitment. Buy her a pair of pink tourmaline earrings to seal the deal!