Ruby signifies passion and unbridled, unrestrained love, making a pair of ruby earrings a perfect Valentine's day gift. 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 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.