Opal is a treasured gem all over the world. A symbol of hope, purity, and love, opal earrings make an elegant and luxurious gift. 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. 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.