How to Tell If a Diamond Is Real: Quick and Easy Tests

Diamonds are one of the most valuable gemstones, but with high-quality alternatives like moissanite and cubic zirconia on the market, it’s important to know whether your diamond is real. Whether you’re buying a new piece or testing an existing one, there are simple ways to check its authenticity before heading to a jeweler.

At Humble Legends Jewelry, we offer affordable moissanite diamonds that look just like real diamonds—without the high price tag. Keep reading to learn how to tell if a diamond is real!

How to Test If a Diamond Is Real

Here are some easy at-home and professional tests to determine if your diamond is genuine:

1. The Fog Test

Hold the diamond up to your mouth and breathe on it like you would a mirror.

If the fog disappears instantly, it’s likely real.

If it stays fogged for a few seconds, it may be fake.

Real diamonds disperse heat quickly, so condensation shouldn’t last long.

2. The Water Test

Fill a glass with water and drop your diamond inside.

A real diamond will sink.

A fake diamond (like glass or cubic zirconia) will float or stay suspended.

Diamonds are dense, so they should immediately fall to the bottom.

3. The Sparkle Test

Hold the diamond under bright light and observe its sparkle.

A real diamond has a unique brilliance with white (brightness) and rainbow (fire) reflections.

A fake stone may appear dull or overly colorful.

Moissanite has a stronger rainbow effect, while cubic zirconia lacks the sharp sparkle of a diamond.

4. The UV Light Test

Shine a UV (black) light on the diamond in a dark room.

Many real diamonds glow blue under UV light.

If there’s no glow, it could still be real, but fakes won’t have the same fluorescence.

Since not all diamonds fluoresce, this test isnt foolproof but can help.

5. The Newspaper Test

Place the diamond over a newspaper or printed text.

If you can’t see the letters clearly, it’s likely real.

If you can read through it, it’s likely fake.

Real diamonds refract light so strongly that they distort images underneath them.

6. The Heat Test

Heat the diamond with a lighter for 30 seconds, then drop it into cold water.

A real diamond wont be affected.

A fake stone may shatter due to heat expansion.

Diamonds can withstand extreme temperatures, while glass and weaker materials can’t.

7. The Professional Diamond Tester

A diamond tester is a small device that checks heat conductivity.

If the device beeps or shows a positive reading, your diamond is real.

If it stays silent, the stone is likely fake.

This is one of the most reliable at-home methods.

8. Get a Professional Appraisal

For 100% accuracy, take your diamond to a certified gemologist. They will use specialized tools, such as:

Magnification (10x loupe) to inspect inclusions

Electronic diamond testers for conductivity

X-ray analysis for structural testing

If you’re unsure, a professional opinion is always the best option!

Moissanite: The Best Alternative to Real Diamonds

If you want the brilliance of a diamond without the high cost, moissanite is a fantastic option. Moissanite stones are nearly as hard as diamonds, more affordable, and have a stunning sparkle.

At Humble Legends Jewelry, we offer high-quality moissanite jewelry that looks just like real diamonds at a fraction of the price.

Check out our moissanite collection today!

Final Thoughts

Knowing how to tell if a diamond is real can save you from costly mistakes. From simple at-home tests to professional evaluations, there are many ways to check authenticity.

If you love the look of diamonds but want an affordable alternative, explore our moissanite jewelry at Humble Legends Jewelry—the perfect blend of luxury and affordability!