Do Fake Diamonds Shine Like Rainbows? – Quick Answer & Tips

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Can you spot a fake diamond within minutes of holding a diamond ring in your hands, or do you prefer shopping alongside someone more knowledgeable to avoid getting duped?

If you fall in the second category, you are in the right place because it is your chance to gain knowledge and new skills about diamonds finally, and the best part is that you don’t have to go to a specialty school to gain this knowledge.

Today, we’ll guide you on how to identify fake diamonds by focusing on just one quality – how true diamonds behave when exposed to light.

This is an important subject because, at the end of the day, some diamonds have a rainbow outline when struck by light, while others don’t. So, let’s take a look at the details.


Is it common for a diamond to reflect a rainbow color?

Do Fake Diamonds Shine Like Rainbows

This is a common question posed when trying to understand how diamonds behave when they reflect light. The answer to this question is yes – it is common for diamonds to have a rainbow-colored reflection.

Ultimately, the color and clarity qualities of the diamond will differ depending on the stone and the cut, but as long as the stone is struck by light at any angle, it will sparkle, and if you look at the stone under direct light, you will notice the colors of the rainbow.

This is the case because of a unique quality of the gemstone called brilliance. Brilliance is the most important quality in diamonds, with diamonds boasting superior quality cuts, clarity, and color, offering the brightest rainbow sparkle.

Do Fake Diamonds Shine Like Rainbows

But there is more to this; when there are no other surfaces around the diamond, a genuine diamond will reflect light, but not in the rainbow-colored brilliance. In a dark space, for example, light hitting a genuine diamond gemstone will be reflected in gray and white tones.

As mentioned above, the diamond’s brilliance depends on the stone’s cut. So, for real diamonds, you will notice the diamond sparkle when the light gets deflected onto a different surface = think of it this way; color shoots from the diamond when direct light hits the gemstone, and then there is a flash of color. And in diamond lingo, that flash of color is referred to as fire.

Do Fake Diamonds Shine Like Rainbows

But just because the diamond sparkles brightly doesn’t mean that this is the only quality that points to the gemstone’s value.

Even if the diamond has a high brilliance and fire, you should talk to the jeweler about the other important qualities of the diamond that actually determine its value, such as the clarity, cut, and color of the diamonds.

All these factors are essential because diamonds will sparkle in the presence of light, whether the diamonds are lab-made or genuine.

So, even if the fake diamonds will only imitate the genuine diamonds’ brilliance, it is something that may lead you down the wrong path, so don’t rely on this quality.


Do fake diamonds shine rainbow? Why?

Do Fake Diamonds Shine Like Rainbows

Fake diamonds, also called diamond simulants, will give off a bright rainbow sparkle when exposed to direct light.

In the case of Cubic Zirconia stones (CZ), the shine of the stone will feature some rainbows, but it won’t be as bright as the diamond sparkle of the real diamonds.

In the case of the Moissanite stones, on the other hand, the diamond shine will be brighter and bigger than the sparkle of the real diamonds.

So, because the fake and the genuine diamonds all have that diamond shine, you may want to look at more features and qualities of the diamonds to determine if they are genuine.


Brilliance of diamonds

Do Fake Diamonds Shine Like Rainbows

As mentioned above, the diamond’s brilliance is the most important quality of the gemstones, and it is largely determined by the clarity and the color of the diamond, and these two elements allow for the display of the diamond effect – brilliance.

Generally, diamonds with better cuts have a much better rainbow effect, which means that the color diamonds that fall in the D-F color grades have a nice rainbow effect, while the colorless G-I graded diamonds have an even better level of brilliance and a stronger rainbow effect.

So, when you look at the diamonds under natural light, the diamond will have bright and beautiful colors. The brilliance and rainbow effect is slightly diminished in diamonds graded lower in color and clarity.

So, how do you identify fake from genuine diamonds at home?


Ways To Spot A Fake Diamond at Home

1. Look at the diamonds through a loupe

Do Fake Diamonds Shine Like Rainbows

A loupe, also called a magnifying glass, is a simple tool that you can buy online or from the nearest online store, and it will allow you to identify the diamond’s features easily and whether it is real or not.

Looking at the diamond under a magnifying glass, you will notice a number of things, one of which is the nature of the diamond, including the imperfections present in the diamond stone.

Do Fake Diamonds Shine Like Rainbows

If the stone you are looking at is a sight of perfection at 100%, then you would be looking at a fake diamond. The fake or lab-grown diamonds are 100% perfect under the loupe, so be cautious about it.

Other than the nature of the diamond and how it looks under the loupe, you also need to consider other elements like e the edges, mountings, and the etchings of the stone.

Regarding the edges, you should observe the stone under the loupe. A genuine/ real diamond features shape edges, while fake diamonds have perfectly rounded edges.

Do Fake Diamonds Shine Like Rainbows

Mountings and etchings are also a great way for you to tell more about the quality of the diamond and if the stone is real or not. Using the loupe, you should look for any markings that will point you in the direction of the quality of the ring and the metals used for the ring.

For diamond rings set in silver or gold-plated metals, it often means that the ring is not made of a real diamond but a fake.

Just think about it, you wouldn’t mount a real, high-quality diamond on some cheap metal. In most cases, real diamond gemstone rings are often set or mounted on high-quality metals like platinum or solid gold.


2. Rub the diamond using sandpaper

Do Fake Diamonds Shine Like Rainbows

Other than looking at the stone under the magnifying glass for imperfections or perfections, marks, etchings, and how the edges look, you can also determine if the diamond is real or fake by rubbing the stone using sandpaper against a stone.

This is an easy but effective test because a diamond is the hardest material on earth, meaning it will not be easily scratched when you rub it against a hard surface.

If the diamond is real, it will not get scratched, but if it’s made of a fake material like cubic zirconia, then it will easily scratch up.


3. Fog Test

Do Fake Diamonds Shine Like Rainbows

Fake diamonds fog up quite easily and fast, but genuine diamonds will not fog up because they don’t retain heat.


4. Sparkle under the light

Do Fake Diamonds Shine Like Rainbows

To reiterate, natural diamonds reflect light in a very unique way such that when they are struck by light directly, light inside the stone will be reflected, and it will appear white or gray (brilliance), while the outside of a diamond will reflect light in some sort of rainbow color show (the fire).

With fake diamonds, the diamond color is also seen inside the diamonds.



There is a huge misconception about diamonds and the fact that they always sparkle like big rainbows, but this is far from the truth because natural diamonds will sparkle with white or gray color on the inside, and depending on the objects in the surrounding, there will be some rainbow effect on the outside of the stone.

Only fake diamonds will have the diamond sparkle from the inside out.

For more diamond rings topics, please visit this section or this page!

Hey! I finally find the Answer!