Diamonds are one of the most desired gemstones in the world—symbols of love, commitment, and timeless beauty. But with the growing popularity of lab-grown diamonds and imitation stones like cubic zirconia or moissanite, it’s natural to wonder: how to tell if a diamond is real?

Whether you own a diamond ring or are considering a new purchase, understanding how to test and identify a real diamond is essential. In this guide, C6 Diamonds explains simple at-home methods and professional testing techniques that can help you know if your diamond is genuine.

How Do You Know If a Diamond Ring Is Real?

Before jumping into tests, it’s helpful to understand what makes a real diamond unique. Real diamonds—whether natural or lab-grown—are made of pure carbon crystals formed under intense heat and pressure. They have remarkable hardness, brilliance, and fire that imitations simply can’t replicate perfectly.

You can find out if your diamond ring is real by combining a few physical tests, visual inspections, and professional appraisals. Let’s go step-by-step.

The Fog Test – Simple and Quick

One of the easiest ways to test if a diamond is real is by using your breath.

How to do it:

• Hold the diamond close to your mouth and breathe on it as if fogging a mirror.
• Observe how long the fog stays on the surface.

Result:

• A real diamond disperses heat instantly, so the fog should clear almost immediately.
• A fake diamond (like glass or cubic zirconia) will stay fogged for 2–3 seconds longer.
  
  

While this test is easy, it’s not foolproof—but it’s a great quick check!

The Water Test – Checking Density

This test uses the principle of density to identify real diamonds.

How to do it:

• Fill a glass with water.
• Gently drop your loose diamond into the water.
  

Result:

• Real diamond: sinks to the bottom due to its high density.
• Fake diamond: often floats or stays suspended in the middle.
  

Keep in mind, this method won’t work for mounted stones, only for loose diamonds.

The Light Test – Watch the Sparkle

A real diamond exhibits a unique brilliance. It reflects both white light (brilliance) and colored light (fire) beautifully.

How to test:

• Hold your diamond under a bright lamp or sunlight.
• Observe how it sparkles and reflects light.
  

Result:

• Real diamonds produce a balanced mix of white and rainbow reflections.
• Fake stones often appear dull or have rainbow colors that look too vivid or glassy.
  

At C6 Diamonds, we craft lab-grown diamonds that display the same brilliance and fire as mined diamonds—because they’re identical in composition and beauty.

The Scratch Test – Understanding Hardness

Diamonds are the hardest natural material on Earth, scoring 10 on the Mohs hardness scale.

How to do it:

• Try gently scratching a piece of glass with your diamond.
• Observe if it leaves a scratch mark.
  

Result:

• Real diamond: easily scratches glass.
• Fake diamond: may not leave a mark.

Caution: Avoid using this test on mounted jewelry, as it can damage your setting or the diamond itself.

The Newspaper or Read-Through Test

This classic method helps to check how light passes through a stone.

How to do it:

• Place your diamond face-down on a newspaper or a page with fine text.
• Try to read the letters through the stone.
  

Result:

• Real diamond: refracts light so strongly that the text will appear blurry or completely unreadable.
• Fake diamond: allows you to see the letters clearly.
  

This simple trick works best on loose diamonds with clean surfaces.

The UV Light (Blacklight) Test

Many real diamonds show a faint blue fluorescence under UV light.

How to test:

• Place the diamond under a UV or blacklight
• .Observe its reaction.
  

Result:

• Real diamond: may emit a soft blue glow.
• Fake diamond: might show no glow or display different colors like green or yellow.
  

Not all genuine diamonds fluoresce, so this test isn’t 100% reliable—but it adds another clue.

Professional Testing – The Most Accurate Way

If you want complete certainty, visit a professional jeweler or gemologist. At C6 Diamonds, our experts use advanced equipment to determine authenticity with precision.

Here are the professional methods used to test real diamonds:

a. Thermal Conductivity Test

Diamonds conduct heat much faster than fake stones. A jeweler uses a diamond tester to measure how quickly the stone disperses heat.

b. Electrical Conductivity Test

This test differentiates between diamonds and moissanite. Moissanite conducts electricity; diamonds don’t.

c. Magnification Test

Under a jeweler’s loupe, a real diamond will show tiny imperfections or inclusions, while fake stones often appear flawless or have rounded facet edges.

d. Certification Check

Always ask for a diamond certification from trusted labs such as GIA, IGI, or GCAL. These documents confirm your diamond’s authenticity, cut, clarity, and carat weight.

How to Identify a Real Diamond at Home (Without Tools)

If you don’t have access to professional equipment, here’s a quick checklist you can follow at home:

•  Fog test – clears quickly
•  Water test – sinks to the bottom
• Light test – balanced brilliance and fire
• Read-through test – can’t see text clearly
• No scratches or chips easily

If your stone passes most of these tests, it’s likely a real diamond—or a lab-grown diamond, which is just as real as mined ones.

Real Diamonds vs Lab-Grown Diamonds

Many people confuse lab-grown diamonds with fake diamonds. The truth is, lab-grown diamonds are 100% real—they have the same chemical composition, brilliance, and hardness as natural diamonds.

At C6 Diamonds, all our lab-grown diamonds are certified, sustainable, and ethically created using cutting-edge technology. The only difference is their origin—not their beauty or quality.

Why Choose Certified Diamonds from C6 Diamonds

When you purchase a diamond from C6 Diamonds, you can rest assured you’re getting a real, certified diamond that’s tested and verified for authenticity. Each piece is crafted with care and backed by global grading standards.

We specialize in lab-grown diamonds, offering timeless elegance with a modern, ethical approach. Whether you’re choosing an engagement ring, pendant, or earrings, every C6 diamond sparkles with genuine brilliance.

Conclusion

There are many ways to tell if a diamond is real—from simple at-home tricks to advanced professional tests. The key is to combine multiple methods for accurate results.

If you want complete peace of mind, always purchase from a trusted jeweler like C6 Diamonds, where every stone comes with certification and transparency.

So the next time you wonder, “How to tell if a diamond is real?”, remember: look for brilliance, check density, test heat conductivity, and trust certified experts.

Your diamond should shine as truly as your love—and at C6 Diamonds, we make sure it always does.