How to Authenticate a Diamond

Hold the diamond between your thumb and forefinger. Bring the diamond close to your mouth. Gently breathe on the diamond.

Look for fogging on the diamond. An authentic diamond does not remain fogged for more than two to four seconds. Heat disperses quickly from diamonds. Glass or other man-made materials stay fogged for much longer.

Hold the loose or mounted diamond up into the light. Look through the top of the diamond. Try to find the bottom of the diamond. With a fake diamond, you will see the bottom.

Observe the color that is reflected within the diamond. Authentic diamonds feature more shades of grey than fake diamonds. Fake diamonds feature a wider spectrum of colors.

Look at how the light is dispersed throughout the diamond. Colors are dispersed throughout authentic diamonds while fake diamonds only feature color toward the top.

Place the diamond on a small kitchen scale. Weigh the diamond. Cubic zirconia and synthetics such as Asha diamonds weigh more than natural diamonds. Cubic zirconia weighs 1.5 times more than an authentic diamond. For diamonds in a setting, subtract the weight of the setting.

Use the scratch test. Drag a loose diamond across a piece of glass. If the glass scratches, the diamond is authentic. Observe the diamond before performing the scratch test. Any scratches on the diamond are an indicator that the diamond is fake.

Use a diamond tester. Diamond testers are simple hand-held gadgets that test the authenticity of a diamond. Diamond testers test the rate that heat flows through the diamond, which distinguishes authentic from fake diamonds. Hold the tip of the tester up to the diamond. The tester beeps and flashes a green light when the diamond is real.

Turn loose diamonds over. Place the flat top on a piece of newspaper. Fake diamonds act as a magnifying glass and magnify the print.