A: For geeks like our CZ stones quality control team, here are a few physical properties of the cubic zirconia manufactured for use in our finished cubic zirconia jewelry, and sold as loose stones from our website: Mohs Hardness: 8-8.5. Refraction index: 2.17. Density,g/cm: 5.9-6.3. Lab diamonds will reflect more light, thus, showing more brilliance and sparkle. Meanwhile, while cubic zirconia looks like a diamond to the naked eye, it won’t reflect as much light. Moreover, lab diamonds will reflect a rainbow of colors, while cubic zirconia primarily reflects blues and oranges. The Water Test: Cubic zirconia is around 1.7 Cubic zirconia tends to retain heat longer than a diamond and will stay cloudy. If you have access to a black light, take a look at the diamond beneath it. Real diamonds should turn blue. However, the brighter the blue, the less pure the diamond. Those of extremely high quality will, ironically, fail this test. Cubic zirconia, often abbreviated as CZ, is a synthetic gemstone that closely resembles diamond. It’s composed of zirconium oxide (ZrO2) and is valued for its brilliance and affordability. CZ has been used in jewelry since the 1970s as a cost-effective alternative to diamonds. Its crystalline structure and optical properties give it a sparkle As mentioned above, cubic zirconia looks quite similar to actual mined diamonds, and lab grown diamonds, to the point that the untrained eye probably wouldn’t be able to tell the difference. In addition, cubic zirconia is colorless, which may appeal to buyers who are searching for a classic style and aren’t interested in the tint or tone Discover the key differences between lab diamonds and cubic zirconia for informed gemstone choices. Skip to main content +1 201 2855165 Hot Call. Search Log In. Sign up. While cubic zirconia is measured in carats, each carat of cubic zirconia is actually smaller than a real diamond of the same carat size because cubic zirconia is denser. For cubic zirconia, color, and clarity do not apply. Cubic zirconia is man-made with a different formation process than real diamonds. As such, it’s always colorless and Four Ways to Tell the Difference Between CZ and Diamond. 1. The Sharpness of Facet Junctions Test. Many of today’s CZ stones have ‘softer’ facets than diamonds. Try the Huff Test: 2. The Huff Test. Hold the stone in question next to a diamond and “huff” on them with your hot breath. Both stones will fog up. Cubic zirconia is nothing like real diamonds in terms of chemical composition. While both CZ and lab diamonds are created in a lab, lab diamonds are created with pure crystallized carbon, which is the same element natural diamonds are grown from. That means, their physical, optical and chemical properties are the same as earth mined diamonds mNJ6.