Cubic zirconia is a crystalline form of zirconium diozide. It is hard and appears flawless. Cubic zirconia is usually colorless, but may be made in a number of different hues. Because cubic zirconia is relatively low in cost, as well as durable and gives the appearance of a diamond, so it is quite popular. It is occasionally called `diamonique`. The price for a 3 carat cubic zirconia ring is usually between $50 and $200.