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. 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.