Image via WikipediaCubic zirconia (CZ) is quickly becoming more popular as a substitute for diamond because of it's closer characteristcs to a diamond than any other gem.
Even trained gemologists, cannot tell the difference between a diamond and CZ with the naked eye. To the untrained eye, CZ looks identical to a good quality diamond. THough, under closer inspection, CZ appears to have slightly less brilliance than a diamond, and has more flashes of color.
The Russians originally developed CZ for their space program, as an alternative to diamonds that were used in the optics of their lasers. CZs have a refractive index, dispersion and hardness so close to a diamond it's uncanny.
What are some key features that can guide you in telling the difference between diamond and CZ? In order to accurately distinguish the two gems, microscope, or loupe, must be used for testing and verification.
To start, let’s take a look at the hardness factor: Did you know CZ ranges between 8.5 to 9.0 on the Mohs’ hardness scale whereas diamond, one of the hardest materials known to man, is rated 10.
Furthermore, glass (or sand) is rated approximately 5 to 6 on the hardness scale, therefore, dust and dirt will not scratch CZ. Indeed, CZ ca
Image via Wikipedian scratch glass just like regular diamonds, making it more resistant to chipping.One great difference between diamond and CZ is weight. CZs are heavyweights in comparison to diamonds; a CZ will weigh approximately 1.75 times more than a diamond of equivalent size. So basically, a piece of CZ the same size as a one-carat diamond weighs about 1.75 carats. Well…isn’t that interesting?
Contemporary production of CZ is virtually flawless, whereas diamond usually contains impurities and inclusions, or have some sort of defect, be it a feather, included crystal, or perhaps a remnant of an original crystal face (e.g. trigons).
In regards to color—more precisely, the lack of color—only the rarest of diamonds are truly colorless, as most have a tinge of yellow or brown to some extent. By comparison, CZ in most cases can be made entirely colorless, equivalent to a perfect "D" on diamond's color grading scale.
On another note, the facet shapes of some CZs appear different from diamonds under close inspection with a loupe. Both gems disperse light a little differently. With a dispersive power greater than diamond (0.060 vs. 0.044), the more prismatic fire of CZ can be seen by even an untrained eye.
CZs are not only durable and inexpensive, but just like diamonds, they come in any color of the rainbow, making them even more desirable.
Another difference between the two gems is that CZs are thermal insulators—they reduce the rate of heat transfer—whilst diamonds are among the most efficient thermal conductors—they allow heat to easily pass through them. It can be difficult to tell them apart without testing the gems’ heat conductivity.
Remember, it is a 50/50 guess to identify a gem by visual inspection; it is not a scientific method of authentication. That is why even certified and degreed gemologists use gemological equipment for testing and verification.
There have been many instances to see if jewelers can tell the difference between diamond and cubic zirconia, just by examining the gems with the naked eye. The difference between diamond and cubic zirconia rests in the price, and in the mind…
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