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. A pair of sapphire earrings set in yellow or white gold is a classic, and is always appropriate. Choose from genuine sapphire, or the more affordable lab-created gem. 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.