Ruby signifies passion and unbridled, unrestrained love, making a pair of ruby earrings a perfect Valentine's day gift. The birthstone of February, amethyst makes an appropriate and affordable gift. A pair of amethyst earrings in a stud or dangly design are always popular and always in style. 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.