With the gemstone market filled with imitations, synthetics, and treatments, knowing how to distinguish authentic gems from fakes is essential. While professional gemologists have specialized equipment, there are several tests you can perform even without expert tools.
Key terms to understand:
Examine the stone in good lighting. Natural gemstones often have slight imperfections or inclusions, while many synthetics are too perfect. Look for bubbles, which indicate glass or some synthetic materials. Check for color consistency—many fake stones have uneven color distribution.
Real gemstones often feel heavier than fakes of the same size. For example, a real diamond will feel heavier than a similar-sized cubic zirconia. This is because natural gems typically have higher density than their imitations.
Touch the stone to your cheek or lip. Natural gemstones feel cold initially and warm up slowly, while glass and plastic imitations warm up quickly. This is due to the thermal conductivity differences between genuine gems and synthetic materials.
Each gemstone has a specific hardness level on the Mohs scale. A real gemstone can only be scratched by materials of equal or greater hardness. For example, a genuine sapphire (hardness 9) cannot be scratched by a knife blade but can scratch glass easily.
Breathe on the stone to create condensation. Real diamonds disperse heat quickly and the fog will disappear almost immediately while glass or plastic will retain the fog for a longer time.