Never more popular, the Sapphire halo rings feature a beautiful gemstone surrounded by sparkling diamonds. 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.