How to Tell if a Diamond is Real or Fake in 3 Steps

Diamonds

/ 21 August 2025

How to tell if a diamond is real or fake? The answer is simple, but what’s more challenging is determining just how beautiful a real diamond truly is.

Many people have wondered, “How do I tell if a diamond is real?”

If buying a natural diamond engagement ring symbolizes love and stability, does a fake diamond ring imply false love and unfaithfulness?

What would you do if you discovered later that the engagement ring you bought was worth only a fraction of what you paid – because it’s fake?

One thing we all have in common is that no one likes being deceived.

However, some merchants don’t always act in good faith. They sell fake diamonds at lower prices, but they claim that these diamonds are real. That’s why, before you buy a diamond, it’s crucial to research where you should purchase your diamond from.

To protect you from being misled when buying diamonds, we’re here to share tips on how to tell if a diamond is real or not. These methods can ensure that what you’re paying for is worth every penny.

How to Tell if a Diamond is Real in 3 Situations:

Larger diamonds over 0.18ct
Smaller loose diamonds that haven’t been set
Diamonds already set in a ring

How to Tell if a Diamond is Real? – Larger Diamonds

Credit: Pinterest

When buying an expensive, large diamond, this is what we call a “High Engagement Purchase.” It’s a decision that takes time, perhaps days or even weeks. A trustworthy merchant will give you the time to consider your purchase; they should never rush you.

Identifying whether a diamond is real is fairly straightforward these days. That’s because most diamonds over 0.30ct come with a certification from an official grading institution. If you know your diamond has a certification, here are two easy steps to confirm whether the diamond is real.

1. Ask for Certifications from GIA/HRD/IGI

Before making your purchase, ask if the shop can provide certification. Reliable diamond stores will offer certifications from well-known institutions like GIA, HRD, or IGI, which are highly respected in the diamond industry.

Make sure the certification is genuine and from a recognized lab. Some shops create their own certificates, which can overvalue the diamonds. This practice is misleading and should be avoided.

2. Check the Edge of the Diamond for Laser Inscriptions

For diamonds certified by GIA, we recommend using a 10x magnifier. You can check for the diamond’s 10-digit laser inscription by viewing the edges with the magnifier. These digits should match the numbers on your certification, ensuring that they are in alignment.

This method works best for diamonds in prong settings, as the diamond is lifted, allowing you to view the inscriptions. If the diamond is in a channel setting, this method won’t work since the edges are concealed, preventing easy viewing.

Therefore, when determining “How to tell if a diamond is real?”, it’s important to consider the diamond’s setting and choose the appropriate method.

How to Tell if a Diamond is Real? – Smaller Diamonds

Checking smaller diamonds, such as those between 0.01ct and 0.02ct, can be more difficult. Even experts need to focus all their attention using a 10x magnifier.

For an easier approach, here are some “common sense” methods combined with technology (if available) that can help you determine if a small diamond is real or fake.

1. Place the Diamond on Ballpoint Pen Ink (Dot Test)

This is the simplest way to check if a diamond is real. Draw a small dot on white paper using a blue ballpoint pen, then place the diamond face down on the dot.

A real diamond with 58 facets will reflect light in all directions, making the dot disappear from view. However, if it’s an artificial diamond or Cubic Zirconia (CZ), the ink will be clearly visible, as if viewed through glass.

2. Weigh It (Precision Test)

If you’re at a diamond store, you can ask to weigh the diamond. This will give you a general idea of whether the diamond is real or fake.
A 1 carat diamond typically weighs around 0.20 grams, while a 1 carat CZ weighs nearly twice as much—about 0.40 grams.

This method isn’t always perfect, especially if your diamond isn’t exactly 1 carat or you don’t know the precise weight.

3. Use a Diamond Tester

While not everyone has access to a diamond tester, it’s a reliable tool for confirming whether a diamond is real. Earlier models test the electrical and thermal conductivity of the diamond. Advanced models may even check the diamond’s reflectivity.

If possible, test both the electrical and thermal conductivity, as fake diamonds made of “Moissanite” may have the same thermal conductivity as real diamonds but differ in electrical properties.

If you’re curious to test if your diamond is real or fake, we recommend using a diamond tester with light indication and humidity stability.

How to Tell if a Diamond is Real? – Set Diamonds

Identifying a diamond that’s already set in a ring can be a bit more challenging. However, here are a few simple methods you can use to check. The success of these methods often depends on experience, but they’re still useful for beginners.

1. Check for Scratches

First and foremost, never intentionally scratch a diamond, whether real or fake, as it may cause unnecessary damage.

However, if you have older diamond jewelry that’s been stored away, take it out and examine it for scratches. If it’s CZ and has been worn frequently, there will likely be visible scratches. Real diamonds, on the other hand, won’t have any scratches, since diamonds are the hardest known material, as proven by science. That’s where the phrase “diamonds cut diamonds” comes from—it’s the only material that can scratch a diamond.

2. The Breath Test

Diamonds have excellent thermal conductivity, which means they don’t retain heat. When you blow hot air on a diamond (like fogging up a mirror), a real diamond will fog up briefly, then clear almost immediately.

However, since Moissanite shares similar thermal properties, this method isn’t foolproof.

3. 10x Magnifier (Loupe)

Using a 10x magnifier (or loupe) is one of the best methods and has been used by professionals for years. This technique allows you not only to check if a diamond is real or fake but also to assess its quality.

When magnified, fake diamonds or Moissanite may show a double line on the diamond’s facets. Real diamonds will have a unique, natural texture similar to ice, sometimes with coarse grains visible on the edges. CZ, being artificially created, will appear smoother under magnification.

Conclusion: It’s Easier Than You Think to Tell If a Diamond is Real or Fake

Learning about diamonds takes dedication and experience, as they come in many grades and shapes. Some aspects are more difficult to grasp than others.
However, what’s often more challenging than telling real from fake diamonds is identifying the true beauty and value of a diamond.

Most diamonds you encounter will already be set in a ring, making it essential to have experience in evaluating the clarity and color to properly determine a diamond’s worth.

For those who don’t have extensive experience, you can try the methods we’ve shared above. If you’re still unsure, visiting a reputable pawnshop or jeweler can help you verify your diamond.