Tourmaline is known as the gem of love and commitment. Buy her a pair of pink tourmaline earrings to seal the deal! Opal is a treasured gem all over the world. A symbol of hope, purity, and love, opal earrings make an elegant and luxurious gift. A pair of peridot earrings sparkle by day, and remain brilliant at night. The Romans called peridot the “evening emerald†whose vibrant green color remained visible by lamplight.