A pair of tanzanite earrings makes for an unforgettable gift. A rare and precious gem, tanzanite is sure to please. 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. Durable and affordable, a pair of blue topaz earrings are an excellent gift for a woman with blue eyes, or anyone who enjoys the beautiful color of blue topaz.