How to identify diamond, moissanite and cubic zirconia?

How to identify diamond, moissanite and cubic zirconia?

Identifying Diamonds: A Guide to Recognizing the Real Deal

Diamonds, prized for their brilliance and value, have fascinated humans for centuries. However, distinguishing a genuine diamond from a simulant can be challenging. Here’s a guide to help you identify a real diamond.

1. The Four Cs: Cut, Color, Clarity, and Carat

Understanding the Four Cs is fundamental when identifying diamonds:

  • Cut: The cut of a diamond affects its brilliance. Real diamonds exhibit exceptional sparkle and light reflection due to their precise cutting angles.
  • Color: Diamonds range from colorless to shades of yellow and brown. The most valuable diamonds are usually colorless.
  • Clarity: Natural diamonds have unique internal imperfections called inclusions and surface defects known as blemishes. The fewer the inclusions, the higher the clarity.
  • Carat: This measures the diamond's weight. While larger diamonds are more valuable, carat alone doesn’t determine a diamond's overall quality.

2. Using a Loupe

A jeweler’s loupe, a magnifying glass designed for inspecting gemstones, can reveal a diamond’s internal characteristics. Look for inclusions or imperfections, as these are common in natural diamonds. Perfect clarity might suggest a synthetic stone.

3. Fog Test

Breathe on the diamond to create a light fog. Diamonds dissipate heat quickly, so the fog should clear almost immediately. If the fog lingers, it might be a simulant like cubic zirconia.

4. Water Test

Place the stone in a glass of water. Due to their high density, diamonds will sink to the bottom, while many imitations will float or hover.

5. UV Light Test

Under ultraviolet (UV) light, many diamonds emit a bluish fluorescence. However, not all diamonds fluoresce, and some simulants might exhibit similar properties, so this test should be used in conjunction with others.

6. Heat Resistance

Diamonds are excellent conductors of heat. Gently heat the stone with a lighter for about 30 seconds, then drop it into cold water. A real diamond will remain intact, while a fake might shatter due to thermal shock.

7. Professional Appraisal

When in doubt, seek a professional appraisal. Certified gemologists use advanced equipment and have the expertise to distinguish real diamonds from imitations and synthetics accurately.

8. Certification

Look for diamonds with certification from reputable organizations like the Gemological Institute of America (GIA). These certifications provide an independent verification of the diamond’s authenticity and quality.


Identifying a real diamond requires a keen eye and knowledge of the stone's unique properties. By utilizing the Four Cs, conducting simple tests, and consulting professionals, you can confidently determine if a diamond is genuine. Whether for investment or personal adornment, ensuring the authenticity of a diamond is crucial to appreciating its true value.