If you are searching for a new diamond, you should know the many fakes currently circulating in the marketplace. The most common way to try and dupe unsuspecting shoppers with fake stones is to sell them cubic zirconia, a man-made gemstone. 

When examined closely, diamonds and cubic zirconia have remarkably similar properties, but there are some telltale signs jewelers can use to help differentiate between the two.

Differences Between Cubic Zirconia and Diamond


The Composition and Cubic Zirconia are different; diamond is composed of carbon, and CZ is composed of crystals, making a big difference. The weight of a diamond is heavier than Cubic Zirconia, CZ is 2.6g/cm3, and diamond is 3.52g/cm3. This makes the diamond denser than Cubic Zirconia.


Diamonds are measured in 4Cs (Cut, Color, Clarity, and Carat). They are measured by angles and the brightness of light reflected off the surface of the diamond. Diamond has a superior cut because it shapes up to reflect light better with its precisely angled and sized facets. The shape for cubic zirconia is more of a domed octahedron, not an exact cut.


The size and quality of diamonds are the most critical factors involved in pricing a diamond. CZ stones don’t have many desirable diamonds and cost much less than natural diamonds. A diamond’s price is determined by weight, color, clarity, and cut. CZ stones are cheaper than diamonds due to their weight and lack of transparency.


Diamonds have seen a resurgence with their popularity and appearance on TV shows like ‘Devious Maids.’ Diamonds used to be limited to two colors, but now there are 750-800 different colors that people can choose from. Unlike diamond, CZ is colorless and produces less sparking, making them unpopular. There are many more attractive colors of diamonds, and it makes more sense to go with a colorless stone over a CZ stone.


The clarity is determined by the number of flaws in the stone that can be seen under 10× magnification. The diamond stones vary from diamonds with no visible flaws to diamonds with CZ-like clarity. The opposite of transparency is known as ‘flimsy.’ This mainly occurs when diamonds are cut from the same facets. The cut of the diamond can also cause it to be ‘flimsy’. 

How Can You Tell If a Diamond Is Real?

Look at the Stones under Natural Light

Many people sell fake diamonds and cubic zirconia under the guise of having natural diamonds. The giveaway that a stone is not a diamond is its reflection. Diamonds will sparkle and shine, while cubic zirconia will have duller shadings to them.

Inspect the Diamond

If you are looking at a diamond and still aren’t sure whether or not it’s real, you can use a glass of cold water to verify the authenticity of the jewel. Place the gemstones in a glass of water and watch. If it floats, then it is probably a fake stone. Real diamonds will sink to the bottom of the glass, while cubic zirconia will float to the surface.

Break Out the Magnifying Glass

If a seller can’t tell you where they got their diamonds from, or they won’t provide you with any documentation that proves their authenticity, then try breaking out your magnifying glass. Generally, real diamonds are flawless, while fake stones will have imperfections.

Is Cubic Zirconia Real?

Yes and no. Cubic zirconia is an artificial gemstone with all the same properties as diamonds. It has a hardness of  eight on the Mohs scale, and it can be polished to resemble diamonds only slightly less than diamonds. Cubic zirconia is also equally as hard, but it can be cut in various shapes and sizes.

If you are looking for quality diamonds, Goldsmith Jewelers is the place to check. For more information about our products, contact us today.