What is Cubic Zirconia?

In 1976, Cubic Zirconia was introduced to gem market. Cubic Zirconia, sometime abbreviated CZ, has been most important simulated diamond, or diamond stimulant. Cubic Zirconia is isometric (a crystallographic system characterized by three equal axes at right angles). The reason why Cubic Zirconia is most convincing diamond substitute is due to its properties: H 8, G 5.9, RI 2.16

Sample picture describing Isometric cube

Refractometer - developed by GIA

H: Hardness
G: Gibbs Free Energy (G=E+PV-TS)

E: Internal Energy
P: Pressure
V: Volume
T: Temperature
S: Entropy (a measure of the unavailable energy in a closed thermodynamic system)

RI: Refractive Index (Measurement of reflection ex: n=V/v)
n: index of refraction
V: velocity of light in the air
v: velocity in the dense material

A unique method of melting called "skull melting" is used to make cubic zirconia. The melting point for cubic zirconia is very high, (2750 F). Due to this, conventional crucibles can not be used. The "Skull" vertical copper tube. The material to be melt is put into this "skull", which is heated by radio frequency which brings center of "skull" to necessary temperature. When the material is cooled, crystals grow upward from the bottom, which in turn is CZ. To make cubic zirconia to turn into monoclinic form, calcium oxide is added to the cubic powder. Simply put Cubic Zirconia is great substitute because its hardness. Like diamonds, CZ can with stand scratches and can be polished into brilliance like how diamonds shines.

How can you tell the difference in CZ?

1. If you have loose stone, can't tell if they are cz or diamond, have it weighed.

Most jewelers have scale and you can weight questionable stone on the scale. Cubic Zirconia's weight is much greater than diamond weight. CZ is about 75% more heavier than a real diamond.

2. Look ath the girdle (side of diamond where top and bottom is divided)

If it looks frosted, or subdued whiteness resembling oiled glass, this indicates CZ. This may require considerable experience.

3. Put the stone in your hand and softly blow your breath in

This will creat foggy mist, like you see it on a window. On the real diamond, the foggy mist will disappear immediately and on the fake or on a cubic zirconia, it will linger longer.