Tourmaline is known as the gem of love and commitment. Buy her a pair of pink tourmaline earrings to seal the deal! 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. Opal is a treasured gem all over the world. A symbol of hope, purity, and love, opal earrings make an elegant and luxurious gift.