What is that Rainbow Diamond Light Called? It’s Diamond Fire

diamond fire example

Diamond Fire: When it comes to diamonds, there are so many different terms that you want to familiarise yourself with before making your extravagant purchase, like fire. Have you heard the term diamond fire? Are you wondering what diamond fire is? Does this mean that diamonds are flammable? Well, yes to that one, that’s a different article. I’ll give you a little insight into what it is and why you would want diamond fire when buying a diamond.

When a diamond is exposed to light, it produces a rainbow color effect; this is known as the diamond fire. Diamond fire is one characteristic that gives the most ‘wow’ factor when it comes to buying a diamond. People tend to go for diamonds with lots of fire, but the diamond fire will ultimately depend on certain factors.

Diamond fire is excellent, but there are certain factors that affect the fire inside your diamond Keep reading and I’ll tell you exactly what those factors are.

What makes the rainbow diamond light dispersion (diamond fire) happen?

There are scientific explanations when it comes to diamond fire and light dispersion within a diamond. The most straightforward answer is that when light enters a diamond, the light bends and hits the pavilion facets within. Once it does this, the light will then reflect onto the crown facets and exit the diamond.

It causes the light to break into individual colors and result in you seeing the diamond fire. A rainbow of color. Here’s a video to see for yourself.

How do gemological labs assess and grade diamond fire?

In gemological laboratories such as GIA, they will place the diamond underneath a LED light and visually assess the diamond at all sorts of angles. They can see each part of the diamond and how the fire shows. The grade of the fire will entirely depend on the brightness and color of the light. If it is brighter and more colorful, it will receive a better grade.

Reasons why you might not see fire in your diamond ring.

Lighting Tricks

Although you might have been able to see the diamond fire perfectly while you were inside the jewelry store, this doesn’t necessarily mean you will see the same elsewhere.

The reason the fire is easily seen at the jewelry store is because of their lighting. They set up their lighting in a way that will enhance the diamond’s fire.

Different environments with entirely different lighting will affect how well you can see the fire. For example, if you have dull lighting, it is unlikely that the fire will show as well as bright lighting.

The Diamond is not clean enough to see Diamond Fire

To keep your diamond looking great and to be able to see the diamond fire clearly, your diamond needs to be clean. If there are particles of dirt on the diamond it is going to prevent the light from entering and bouncing back the fire.

How do diamond fire and moissanite fire differ from one another?

Firstly, to start, we want to clarify that although moissanite gemstones look similar to diamonds, they are not diamonds; however, they both have fire.

The difference between diamond fire and moissanite fire is that moissanite fire is more intense. This is because moissanite has a double refractive index.

If you see a rainbow of color when looking into a diamond, then that’s a sign of a fake diamond.

fake diamond fire example

Learn more about spotting fakes:

Can the cut, color, or clarity of a diamond affect the fire?

All diamonds have fire but some more than others. The cut, clarity, and color will affect the diamond’s fire. So, you need to make sure that you pick a diamond with good clarity and color grades if you want a diamond with great fire.


The body color of a diamond can completely affect the fire. It affects how the light enters and reflects off of the facets. Especially in fancy colored diamonds such as pink and yellow diamonds. However, Diamonds on the colorless spectrum will not be badly affected by the different color grades.


The lower the clarity is for a diamond, the less fire there will be in the diamond. So if fire is what you want when buying your diamond, I would recommend that you need to pick a diamond with a high clarity grade. I recommend a clarity grade of VS2 or higher to get some good fire going on.


The cut of the diamond affects how the light passes through the diamond. A Round cut is the best cut to buy if you’re going for maximum fire. Round cuts have the highest brilliance and sparkle making them the most popular cuts of diamonds.

Where are the best places to buy high-quality diamonds with sparkle and fire?

You can almost buy diamonds anywhere these days. Lots of businesses sell diamonds, both in-store and online, but some will sell low quality, and others will sell higher quality diamonds. Ideally, if you want high-quality diamonds with sparkle and fire, I would recommend the vendors listed below. I think both of these diamond sellers have exceptional quality diamonds, and the perfect websites to help you find exactly what you are looking for.

James Allen

James Allen is great if you are shopping online instead of a store. They have a team of experts on hand to help your every need, along with a 360-degree video of each diamond they sell. Perfect when looking for sparkle and fire. See also: Why are James Allen Diamonds So Cheap

Blue Nile

Like James Allen, Blue Nile also contain videos of each of their diamonds; however, the extra part they do is showing the diamond in a variety of lighting which means you can correctly see what the diamond fire looks like in multiple environments. Blue Nile is well known for its beautiful diamonds, which have a high-quality cut to allow for the best fire.

Carl A. Jones, GIA GG

Carl A. Jones is a GIA Graduate Gemologist with over 20 years of experience in the diamond industry. He is an independent jewelry appraiser. He specializes in determining the value of diamonds and advising consumers on how to buy quality diamond jewelry.

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