A pair of black onyx earrings are an affordable and elegant gift. Always appropriate and always in style, black onyx should be in every jewelry box. 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. Ruby signifies passion and unbridled, unrestrained love, making a pair of ruby earrings a perfect Valentine's day gift.