- Cubic zirconia can be manufactured to be completely colorless. Only extremely rare diamonds are totally colorless; most have a brown or yellow tinge.
- Diamonds are good thermal conductors, which means heat easily passes through them, but cubic zirconias act as insulators and will reduce the rate of heat transfer.
- Diamonds tend to have impurities or defects, like a feather (an area that blocks the light), whereas man-made cubic zirconia are essentially flawless.
- A CZ weights about 1.75 times more than a diamond of the same size; if you had a cubic zirconia that was the size of a two-carat diamond, the CZ would weigh about 3.5 carats.
- Diamonds have a 10 rating on the Mohs hardness scale. Cubic zirconia rate 8.5 to 8.9.
- A cubic zirconia's refractive index is 2.176, but a diamond's is 2.417.
- Diamonds have much less fire than cubic zirconia, which flash only orange. Diamonds will flash orange and blue.














