Cubic Zirconia (CZ) has become a popular gemstone due to its striking resemblance to diamonds. Whether you’re a gem enthusiast, a jewelry collector, or simply want to make informed purchases, knowing how to identify Cubic Zirconia is essential. In this comprehensive guide, we will explore various methods and techniques to distinguish this synthetic gemstone from its natural counterparts.
Characteristics of Cubic Zirconia: Before delving into identification methods, it’s crucial to understand the distinctive features of Cubic Zirconia:
- Crystal Structure: Cubic Zirconia has a crystalline structure that closely mimics that of diamonds. Its square or rectangular facets contribute to its diamond-like appearance.
- Hardness: CZ is relatively hard, scoring 8-8.5 on the Mohs scale. While not as hard as a diamond (10), it’s harder than most other gemstones.
- Brilliance and Fire: Cubic Zirconia exhibits an impressive brilliance and fire, with flashes of color and sparkle when exposed to light.
- Color Variations: CZ is available in a wide range of colors, including colorless, which is often used as a diamond substitute.
Methods to Identify Cubic Zirconia:
- Visual Inspection:
- Double Refraction: Cubic Zirconia typically shows double refraction under a gemological microscope, creating doubled facets and letters when viewed through the stone.
- Fluorescence: CZ may exhibit strong fluorescence under ultraviolet (UV) light, while natural gemstones like diamonds often show weak or no fluorescence.
- Thermal Conductivity:
- Conduct a thermal conductivity test using a thermal tester. CZ has a significantly higher thermal conductivity than diamonds, allowing for differentiation.
- Specific Gravity:
- Calculate the specific gravity of the gemstone by comparing its weight in air to its weight in water. CZ usually has a specific gravity higher than most natural gemstones.
- Hardness Test:
- Use a hardness tester or scratch test to evaluate the gem’s resistance to scratching. While CZ is hard, it can be scratched by harder substances.
- Loupe Examination:
- Examine the gemstone under a jeweler’s loupe for telltale signs of Cubic Zirconia, such as tiny gas bubbles, internal facets, or metallic glints from impurities.