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. White topaz is a popular substitute for the birthstone of April, which is diamond. A pair of white topaz earrings is an affordable alternative to expensive diamond studs.