Cubic Zirconia
Hardness: 8 to 8.5
Cubic Zirconia (CZ) is a synthesized or man made crystalline form of zirconium dioxide. It is hard, optically flawless and usually colorless, and may be made in a variety of different colors. Because of its low cost, durability, and close visual likeness to diamond, cubic zirconia is often used in costume jewelry to get the "bling" look of diamonds at a substantially lower price.