What Is a Blue Diamond

Diamonds come in different colors, including blue. I am not talking about color enhancement or tinting. I am talking about naturally occurring blue diamonds.

So what is a blue diamond? Is it real? In this article, we will take a look at blue diamonds, how rare they are, and the available types.

Blue Diamond: Definition and Origin

A blue diamond is a type of diamond that occurs naturally in that color. It comes in different shades, ranging from the lightest shade of blue to dark blue.

These shades usually have highlights or hues such as green and gray.

Boron in the carbon structure of the diamond gives it a natural blue color. Only a handful of mines have them: South Africa Cullinan diamond mine, India Golconda mine, and Australia Argyle mine.

And because these natural ones are not common, they are truly valuable. How blue the diamond is and its weight also play huge roles in determining its worth.

In other words, the bluer it is, the more value is placed on it.

Blue diamonds come from below the earth’s surface. They are not artificially colored nor are they enhanced for color.

They are not to be confused with sapphires. While blue diamonds have a carbon structure, just like every other type of diamond, sapphires don’t. and the latter contains trace amounts of copper, iron, titanium, and chromium.

This is what a natural blue diamond looks like…

Blue Diamond: Intensity Levels

Blue diamonds are seen as rare. The only other fancy color diamond that is rarer and costlier is the red diamond. But there are different levels to their rarity.

The bluer a diamond appears, the rarer it is. And the rarer it is, the more value it has on the market.

The carat weight also affects its value. It is extremely difficult to find a blue diamond that is higher than 1 carat. If you do find one, I bet it is going to be insanely expensive.

To demonstrate how rare and therefore, expensive it can be, a green-blue diamond of a little of 2 carats and of a cushion cut costs over $400,000. Note that this is not the most intense or purest blue.

The scale for grading blue diamonds ranges from faint blue to fancy vivid blue. You can also see a color called fancy dark blue. But this is possible if there is a secondary color adding to its hue.

However, if there is a modifier or a secondary color added to the blue of the diamond, its value drops.

Because it is more common to see blues mixed with other colors, diamonds that are pure blue are very rare.

Nevertheless, blue diamonds with mixed modifiers are still beautiful, even the common blue-green and gray-blue ones.

Blue Diamond: Types

Blue Diamond Types
something borrowed

Almost every type of blue diamond is a Type IIb. This type accounts for just about 0.1% of all the color diamonds in the world.

Within this type, however, you can begin to classify the diamonds by the color and hues they carry.

But in all, a blue diamond, no matter the intensity, falls under the Fancy Color Diamond family. This is because most diamonds are naturally clear or just slightly colored. So any diamond that has a clear and vivid color is considered fancy.

Natural and Man-made Blue Diamonds

I want to point out here that there are man-made blue diamonds. Not all of them come from below the earth’s surface.

They are made in labs. Usually, a diamond used for this is a colorless diamond. However, under intense heat, the color is added.

If you don’t have an eye for real gemstones, you may not be able to tell the difference between natural and artificial. But here are a few ways to tell the difference.

Color is the primary difference. Blue diamonds that are made in a lab have a different blue hue from the natural ones.

Another difference is the way they conduct electricity. Boron is the substance that makes the diamonds blue, along with nitrogen. But boron also makes electricity conduction easy.

So an artificial blue diamond won’t be able to conduct electricity as well as a natural one.

Important Factors about Blue Diamonds

Important Factors about Blue Diamonds
something borrowed

Here are a few helpful facts about blue diamonds I believe you should keep in mind:

1. Lab-made Blue Diamonds Are Not Expensive

If you bought a blue diamond for a reasonable price, it is probably just an artificial one. True blues are not cheap at all; a 0.35 carat can cost as much as $20,000. Besides, they are very rare so there isn’t much in circulation.

However, the naked eye cannot tell the difference between natural and artificial ones. In fact, I know man people can’t tell if a blue gemstone is a sapphire or a diamond.

2. Natural and Lab-made Blue Diamonds Receive the Same Grading

You already know that the lab-made ones are diamonds, only that they are not naturally blue. So the grading system for both types remains the same.

Therefore, to grade them, you will have to consider their carat weight, cut, color and clarity.

  • Carat Weight

Merely looking at the size of a diamond cannot tell you the weight unless you are an expert.

Because of how rare a natural blue diamond is, the smallest carat weight can pull in a huge price. But a lab-made or treated one is more affordable.

What does this mean? The carat weight of a real blue diamond does not make it less expensive. The same cannot be said for a lab-made one.

The grading is the same for both types. The only difference is in the color. But this applies when you can tell the difference.

  • Cut

The cut of a diamond simply means how beautifully and well its angles align to reflect light.

It is a known fact that the round brilliant cut is the best and affects the price. But this does not exactly affect the blue diamond.

If the pavilion of the diamond is deep, it allows the light on the diamond to travel more. It also makes the color appear more intense than it actually is.

Therefore, in the case of a blue diamond, whether natural or lab-made, trillion, pear, oval, and heart cuts suit it better than round. These fancy cuts make the brilliance better and the color deeper.

Needless to say, the intensified color increases the value of the diamond.

  • Color

There are 3 things to consider when it comes to the color of a diamond, whether it is natural or lab-made. They are:

  • How dark or light the diamond is
  • How bright or dull it is
  • Rainbow color

In other words, the intensity of the blue makes the difference. However, most of the available real blue diamonds are not a deep or intense blue. They are usually lighter, with a grayish secondary hue. They are still highly valuable, though.

Lab-made blue diamonds are usually intensely green-blue. And if you are an expert, you would know immediately that it is artificial.

This is because natural blue diamonds that have an intense color are so rare that many jewelers and collectors have never seen them.

  • Clarity

How clear a diamond is, including a blue one, determines its worth. Treated blue diamonds rank somewhat low on this scale. This is because colorless diamonds with low clarity are usually turned into fancy color diamonds.

The same does not apply to a natural blue diamond. Most of them are clear and have little inclusions, resulting in high clarity.

  • Blue Diamonds Are Great Center and Side Pieces

If you choose to go for affordable blue diamonds, you can use them as pave diamonds.

In fact, whether you use real or lab-made ones, only a handful of people can tell the difference. This is especially true if the diamonds are tiny.

Interesting Facts about Blue Diamonds

Let us look at some interesting facts about blue diamonds.

  • A blue diamond is said to represent spirituality, truth, eternity, and devotion. This probably because of its extreme rarity and the association of the color blue with royalty.
  • Of all the diamonds mined in the world presently, blue diamonds make up below 1%. That is a small number.
  • In 2019, a blue diamond of a little over 20 carats was found in the Cullinan mine outside Pretoria by Petra Diamonds. It sold for about R220million.
  • The Blue Moon of Josephine is a flawless blue diamond that a Hong Kong billionaire bought for his 7-year-old daughter and named it after her. Weighing 12.03 carats, it sold for about $48.4 million in 2015.
  • In 2018, the Okavango Blue was found. But this time, it was found in the Orapa mine in Botswana. The stone weighed 41.11 carats and was oval. It is currently the clearest blue diamond ever found, with VVS2 clarity.

This is what the Okavango Blue looks like…


A blue diamond is a real diamond, very rare and expensive. It is not enhanced or treated in order to receive its color.

Some blue diamonds are lab-treated so are not as valuable as the real blue ones. But if you cannot tell the difference, they all look the same.

However, the cut, clarity, color, and carat weight affect the value of a blue diamond. So bear this in mind if you decide to go for one.

Do you have any questions? I will answer them in the comments section.

Sharing is caring!

Similar Posts