Trained gemologists can tell the difference between the two. They use a magnifying loupe to study the stones carefully. Diamonds are rarely perfectly clear, and will often have small inclusions that are not visible to the naked eye. A cubic zirconia, on the other hand, is perfectly clear, with no imperfections. Facets cut into diamonds are slightly different in shape than those cut into CZ, another clue for gemologists. Reputable companies will never try to pass off a CZ jewelry as diamond jewelry.
A cubic zirconia is measured differently than a diamond. For hundreds of years, diamonds have been sold by weight, measured in carats. CZ is heavier than diamond - about 75% heavier! Because of this, CZ jewelry is sold according to their size, measured in millimeters (mm). For those not accustomed to the metric system, there are 25.4 mm in each inch.
Perhaps the best way to identify cubic zirconia jewelry is by its cost. Diamonds are more expensive. Only a few perfect diamonds can rival the dazzle and flash of CZ, and those perfect stones are expensive. CZ jewelry is comparably economical, and it is available in all your favorite precious metals. Whether your tastes run to sterling silver or gold, necklaces, bracelets, or earrings, cubic zirconia offers serious bling for less ka-ching!
With all the benefits of cubic zirconia, there's no need to deprive yourself of its precious flash and shine.