Cubic zirconia is optically very close to diamonds (diamonds), and the average person may not be able to separate the two. But there are still some differences between the two under the microscope:
Dispersion: The dispersion of cubic zirconia is 0.060, which is higher than 0.044 of diamond. Therefore cubic zirconia appears to be more brilliant than diamonds.
Hardness: Cubic zirconia has a Mohs hardness of 8.5 to 9.0 and a diamond of 10.
Specific gravity: cubic zirconia is 1.7 times heavier than diamond. However, this feature can only be used for gems that are not inlaid separately.
Refractive index: Cubic zirconia has a refractive index of 2.176, which is slightly lower than 2.417 of diamond.
Cutting: Due to the difference in refractive index, the cubic zirconia is cut slightly differently from the diamond and can be found by careful observation under a magnifying glass.
Color: Completely colorless diamonds are very rare, usually with a light yellow color. But cubic zirconia can be caused to the highest level of diamond, namely D-class color.
Heat transfer: The thermal conductivity of cubic zirconia and diamond is two extremes. Cubic zirconia is a superior insulation material that can be used as a jet engine insulation. Diamond is one of the best thermal conductors, and its thermal conductivity exceeds copper. This property best distinguishes both, as long as the appropriate equipment is used.