Cubic zirconia (also called CZ) is a synthetic crystalline substance used as an affordable alternative to diamonds and gemstones. Cubic zirconia is not a mineral; it is a man-made substance, not to be confused with the natural gemstone zircon. Though much less expensive than diamonds, the brilliance and crystal clarity of cubic zirconia make it one of today's most popular stone choices for an attractive, yet inexpensive, diamond-like jewelry.
Most cubic zirconia is bright white to mimic diamond. However, cubic zirconia is also enhanced with other minerals and manufactured in most any color.
Cubic zirconia has a rating of approximately 8 to 8.5 on the Mohs scale of hardness. The denseness of cubic zirconia makes it about 75% heavier than diamonds.