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Fire In A Diamond? What is Diamond Fire?

Fire In A Diamond? What is Diamond Fire?

Few things drive women crazy the way jewelry and diamonds do. It doesn’t matter if they’re young or old: If you want to reach their heart, buying one of these elegant accessories will be a perfect idea.

One thing that makes everyone go crazy about these gems is the beautiful way a diamond catches the light. 

In the process of selecting a diamond, we tend to talk about brilliance quite a bit, but the stone’s attractive sparkle is made up of more than just brilliance. One other factor that plays a role here is fire.

What does fire in a diamond mean? Does it mean it is literally on fire? Of course not! Fire refers to a multitude of colors dancing within it

Think of a rainbow made by the effect of rain or the sprinklers that water your garden. Well, something like that is the fire of the diamond. 

Fire is color! Endless colors that live inside your diamond. Keep on reading to find more about diamond’s eternally-living fire!

Beauty That Comes To Light

For the fire to become evident, it is necessary to resort to light. Most diamonds are transparent, and light can pass through them easier than in sapphire or garnet, for example. That’s why – and how – a diamond’s fire comes out.

Thanks to the light in a diamond, we can see three things – brilliance, fire, and sparkle. What is the difference between them?

  • Brilliance is the ability of the diamond to return the light it captures from any angle, making it appear that it is coming from within.
  • Sparkle represents the flashes of light that occur when a diamond moves under a light source. They bring life and beauty to diamonds.
  • Fire is the dispersion of colors inside when light enters it. Once the light bounces off the interior walls towards the center of the diamond, it shoots through the top. 

Because the diamond cuts slightly bend the light, a spectrum of color is visible when the light exits the top of the stone. And that means the better the cut, the more fire you will see.

Read More: Which Diamond Cut Sparkles The Most?

The Fundamentals Of Light

To better understand the fire of a diamond and how it occurs, we need to discuss the basics of light first.

Visible light is part of an electromagnetic energy spectrum that spreads in waves. White light, in particular, is made up of several wavelengths, each of which corresponds to a different color. 

Light is drastically slowed when it penetrates a transparent medium – such as water, glass, or a diamond. And the more significant the slow-down, the greater the material’s capacity to refract light. 

The light “bends” or refracts as a result of this slow-down. 

When the light is released back into the atmosphere, it accelerates again. Different wavelengths bend at different speeds, becoming separated or “dispersed.”

Because of this dispersion, an observer might perceive a rainbow’s distinct colors, refracted by a prism, and “fire” from a diamond.

The Power Of Fire

Fire in a diamond is, in many ways, comparable to viewing a rainbow after a rainstorm. It’s always stunning in its beauty and brief in its presence – which adds to its uniqueness. 

Fire is light that, like the colors of a rainbow, has been “unbundled” and split into the constituent colors of the spectrum via the prismatic effect. 

You see, as light passes through a rainbow, the vapor in the atmosphere functions as a prism. A faceted diamond also functions as a prism, given that light slows as it enters and speeds up as it exits the facets. 

The perfect alignment of diamond’s facets is essential in influencing the chances of fire events occurring in a diamond.

It’s also worth noting that a diamond has an extremely high refractive index. And the greater the potential for dispersion, the higher the refractive index. 

But while diamond has tremendous potential for fire, the quality of the cut determines whether or not that promise is achieved.

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The Source Of Light

The right lighting conditions are also necessary to observe fire in a diamond. In some lighting settings, a well-cut diamond, such as the aftermath of a rain shower that does not generate a rainbow, will not produce fire.

Singular, small-angular-size direct light sources are more likely to cause this “fire” than huge diffuse ones. For instance, a diamond can display a great fire when exposed to direct sunshine outside. 

The light, however, will be diluted if there is cloud cover. So, while this may be the best condition for examining a gem’s brightness and contrast patterns, it will almost suppress the fire within it.

That said, indoor illumination with a large number of tiny angled lights can create a “fire-friendly” atmosphere that improves our capacity to see fire. 

The Importance Of Virtual Facets

“Virtual facets” are doing the majority of work when it comes to a diamond’s light performance. Now, you’re probably wondering, “What are facets?

The diamond’s sides that reflect light to the eye are known as facets. 

Because a single facet may reflect light beams from many sources and trajectories, the number of virtual facets is substantially higher than the number of physical ones. 

And the bigger the number of virtual facets, the more sparkle scintillation. As a result, the facet design must incorporate some more prominent virtual facets.

Diamond Proportions

The amount and position of dispersion of the light that the diamond returns to the eye can be calculated via ray tracing. 

On that note, the basic proportions must be within a minimal range to create a basis for the development of considerable fire. These proportions generally look a bit like this: 

  • Depth: 59% – 63%
  • Table: 52% – 62%
  • Crown Angle: 31.5% – 36.5%
  • Pavilion Angle: 40% – 42%
  • Girdle: Thin – Slightly Thick
  • Culet: None – Very Small

A perfect cut diamond is proportioned so that nearly all the light that enters it gets returned to the viewer’s eye.

How To Get A Diamond With A Lot Of Fire?

Choose a stone with outstanding symmetry to receive plenty of diamond fire. The symmetry influences how the stone bounces and refracts light, increasing the importance of those critical virtual facets. 

That’s something that a gemologist can assist you with – but generally speaking, your best bet is definitely a triple-X stone. This abbreviation stands for “Triple Excellent,” which means “great cut, symmetry, and polish.” 

That is one of the GIA certification grades that any diamond vendor should go over with you before your purchase.

The Viewer’s Role

The perception of a gem’s colorful fire depends on various elements, one of which is the viewing distance from the diamond. 

And since the spread of spectral color falls over the observer’s pupil, and a specific color is cut, it also relies on the observer’s pupil size.

When a scattered beam of light leaves the diamond, the different wavelengths take on distinct paths, causing them to spread out even more as the distance goes up, increasing the probability of clipping.

That is why, from two or three tables away, you could notice the fire in a diamond on someone’s hand – even in a poorly lit restaurant.

Learn More: What Are Spready (Spread) Diamonds?

How Does Diamond Cut Influence Fire?

When light penetrates a diamond, it is broken down into multiple hues – which causes fire. That is why diamond fire is also known as “dispersion.” As you might expect, this is also why cut is so crucial in determining how much fire a diamond has.

When a diamond is cut in the so-called “perfect proportions,” it bends and reflects light in such a manner that the fire and brightness of the diamond are maximized.

On the other hand, the more the stone’s proportions deviate from those of the “perfect cut,” the less fiery and bright the diamond will appear.

If a diamond is cut too low or too deep compared to the optimal cut proportions, the light would seep out of the bottom of the stone and not return to the observer’s sight. 

As a result, the stone will seem dull and lifeless.

If you want a diamond with a lot of fire and brightness, go for a cut graded Excellent, Very Good, or Good, rather than Fair or Poor.

Which Diamond Cut Has The Most Fire?

The maximum fire is seen in round brilliant cut diamonds. That’s by design: Gemologists have been striving to improve the fire of that cut since it was invented in 1919 by a PhD-educated engineer who utilized mathematical calculations to enhance its shine. 

The round brilliant diamond has 58 facets, which is a large number of physical facets, resulting in even more virtual ones.

Fire Testing In A Lab

The light performance grade system – established by AGS Laboratories – includes the only scientific, peer-reviewed appraisal of fire. 

The ideal (0) grade is only given if the aspect has no severe deficiencies.

The AGSL system might also produce fire maps along with ASET lightmaps for light return, light leakage, and contrast. They denote the portions of the diamond that are capable of creating fire.

Diamond Clarity And Fire

Diamond clarity is an essential aspect that influences fire. A diamond with low clarity will have numerous flaws within the stone, affecting its look and light performance. 

These defects will make the passage of light through the stone considerably more complicated, reducing its brightness, scintillation, and fire and making it far less alluring.

While the diamond fire is primarily used to assess the cut quality of a diamond, it is also used to determine its clarity.

Diamond Brilliance And Fire

The distinction between diamond fire and diamond brilliance can be summed up as follows: While a diamond’s fire refers to the dispersion of white light into all the hues of the rainbow, its brilliance refers to the same white light coming out of the diamond undispersed.

Diamond Sparkle And Fire

The combination of brilliance and fire in a diamond is known as sparkle. The sparkle, also called “scintillation,” is immediately visible when the diamond moves. 

The radiance bounces off the diamond’s body and gives the stone life. Pick up a diamond and move it a bit in your hands; you’ll notice those bright flashes of light right away. 

Read Also: Why Does A Diamond Sparkle?

How To Keep Diamond Fire

Even though your diamond does not appear to be dirty, you should nevertheless clean it on a regular basis. The need to clean diamonds is sometimes overlooked, but it keeps them shining – and the fire burning. 

The fire in your diamond will quickly diminish as the stone surface gets dirty and imperfections become more apparent, making light entry and reflection difficult.

For that reason, it’s best to secure your diamond from external damage or contamination while also making sure to clean it as thoroughly and safely as possible.

Here’s a step-by-step guide on how to clean your diamond so that it retains its fire:

  1. If you’re polishing it over a sink, be sure there’s a stopper inside to keep your diamond or ring from falling down the drain.
  2. Use a safe cleaning solution. Professional diamond cleaning treatments are available in jewelry stores – but you could just use a light liquid soap. Whatever you choose, be sure it’s not too harsh and is suitable for use on a valuable stone. If the diamond is set, ensure that the cleaning solution is suitable for the entire jewelry – not just the gem.
  3. After immersing the stone in the cleaning solution for a few minutes, remove it and clean it with a gentle toothbrush to remove any leftover dirt.
  4. Wash and clean the stone well before drying it with a soft towel.

If you’re concerned that all of this is too unsafe and that you’ll ruin things, jewelry stores usually have jewelry cleaning surfaces for sale at reasonable costs.


The diamond’s qualities are what make people stare at you from across a room. Its sparkle, fire, and brilliance are, in essence, what makes a diamond – a diamond.

So, how important is the fire in a diamond?

Fire is more challenging to obtain, but it becomes a fantastic feature – full of enchantment that captivates with its incredible beauty when it’s achieved. So, it’s safe to say that it’s one of the most desired attributes in a diamond. 

Our gems are given life and a very particular spirit through that fire.

So, be sure to keep your diamond dazzling and alive and clean it frequently to eliminate dust and other dirt that build up over time!