Real diamonds have specific characteristics that set them apart from fake or synthetic stones. Here are the key traits to help identify a genuine diamond:
1. Hardness
- Unmatched Hardness: Diamonds are the hardest naturally occurring substance on Earth, rated 10 on the Mohs scale. They can scratch glass, metals, and other gemstones. Fake diamonds, like cubic zirconia, are softer and may not scratch these materials.
2. Brilliance (Sparkle)
- Unique Sparkle: Diamonds exhibit an exceptional sparkle due to their ability to refract light. The brilliance is a combination of:
- Brightness: White light reflected from the surface.
- Fire: Colored light dispersion that creates rainbow-like flashes.
- Scintillation: The sparkle seen when the diamond moves.
- Comparison: Fake diamonds often lack this level of brilliance or produce a dull, rainbow-like sheen that looks overly artificial.
3. Transparency
- Text Test: Place the diamond over printed text. A real diamond’s high refractive index will scatter light, making the text below nearly impossible to read. Fake diamonds, like quartz or glass, may allow you to see the text clearly.
4. Flaws (Inclusions)
- Natural Imperfections: Most real diamonds have tiny internal flaws called inclusions, which are visible under magnification. These flaws are a natural byproduct of the diamond’s formation. Lab-grown or fake diamonds often lack such imperfections or have perfectly uniform patterns.
5. Thermal Conductivity
- Heat Test: Diamonds are excellent heat conductors. If you breathe on a real diamond, the fog will dissipate almost instantly. Fake diamonds, such as cubic zirconia, retain fog for longer because they don’t conduct heat as efficiently.
6. Weight
- Lighter Than Fakes: A real diamond is lighter than most fake counterparts of the same size. For instance, cubic zirconia is denser than a diamond and feels heavier.
7. Edges and Facets
- Sharp Edges: A genuine diamond’s edges and facets are sharp and well-defined due to its hardness and precise cutting. Fake diamonds often have rounded or less defined edges because softer materials are used.
8. UV Fluorescence
- Blue Glow: Many real diamonds exhibit a blue glow under ultraviolet (UV) light, though not all diamonds do. If the diamond glows a different color (yellow, green, or orange), it might be synthetic or fake.
9. Conductivity Tests
- Electrical Conductivity: Natural diamonds are good electrical insulators but excellent thermal conductors. Specialized diamond testers can identify real diamonds by testing their thermal or electrical conductivity.
- Moissanite Confusion: Moissanite, a common diamond substitute, can also conduct heat and may pass a thermal test. However, it can be distinguished through other methods.
10. Refractive Index
- Light Reflection: The refractive index of a real diamond is high (around 2.42). If you place a diamond face-down on a dot or line, you should not see the dot or line through it. A fake diamond may not bend light as effectively, making the mark visible.
11. Certificate of Authenticity
- Certified Diamonds: Real diamonds are often accompanied by a certification from a reputable gemological institute such as:
- GIA: Gemological Institute of America
- IGI: International Gemological Institute
- AGS: American Gem Society
- This certification details the diamond’s characteristics, including carat weight, cut, clarity, color, and origin.
12. Resistance to Damage
- Chip and Scratch Resistance: Diamonds are incredibly durable and resistant to scratches. Fake diamonds are more likely to chip or show wear over time.
13. Water Test
- Buoyancy: Place the diamond in a glass of water. A real diamond will sink due to its density, while many fakes may float or sink slowly.
14. Color
- Natural Color Variations: Diamonds naturally occur in a range of colors, including colorless, yellow, blue, and pink. A completely flawless, colorless diamond is rare. Synthetic or fake diamonds might appear overly white or uniform in color.
Summary of Real Diamond Characteristics:
- Hardest natural material (scratches other surfaces).
- Exceptional brilliance and fire.
- Natural inclusions visible under magnification.
- Excellent thermal and electrical conductivity.
- Sharp, well-defined edges and facets.
- Often displays a blue glow under UV light.
- Comes with a certification from reputable gemological institutes.
If you’re unsure, a professional gemologist or jeweler can provide a definitive assessment.