There are several key features of cubic zirconia (CZ) which distinguish it from natural diamond:

• Hardness: CZ has a rating of approximately 8 on Mohs scale vs. 10 for diamond.
• Specific Gravity: The density of CZ is about 1.7 times that of diamond.
• Refractive Index: CZ has a refractive index of 2.15-2.18, compared to diamond's 2.42.
• Dispersion: Very high at 0.058-0.066, exceeding diamond's 0.044.
• Cut & Color: CZ is often entirely colorless (equivalent to a "D" grade) and can be produced in various colors like pink, purple, and green.
• Thermal Conductivity: CZ is a thermal insulator, while diamond is a very good thermal conductor.

Cubic zirconia (CZ) is the cubic crystalline form of zirconium dioxide (ZrO2). Since commercial production began in 1976, it has remained the most economically important competitor for diamonds due to its low cost, durability, and close visual likeness.