Check for imperfections: Real diamonds often have imperfections called inclusions, while fake ones may appear too perfect.
Test with heat: Diamonds disperse heat quickly, so try fogging it with your breath. If it clears up immediately, it's likely real.
Test with a magnifying glass: Look for tiny, natural flaws inside the stone. Real diamonds usually have them, while fake ones are often flawless.
Use a diamond tester: These devices measure thermal conductivity and are commonly used by jewelers to differentiate real diamonds from imitations.
Check for reflections: A real diamond's reflections often have gray or white hues, while fake diamonds might produce rainbow reflections.
Consult a professional: If in doubt, take the diamond to a reputable jeweler or gemologist for authentication. They can use specialized equipment to verify its authenticity.