How Much Is a Blue Diamond Worth

One of the rarest diamond colors, a natural blue diamond is among the most sought-after colored diamonds in the world. This lovely and mysterious gem has captured the world’s attention times without number. This is because it makes for an exquisite addition to any jewelry collection.

But then, how much is a blue diamond worth?

The average price of a 0.5-carat light blue diamond is around $26, 280, while that of a 0.25-carat deep or vivid blue diamond can cost upwards of $75,000. Note that blue diamonds with lighter colors – otherwise known as blue diamonds with modifiers – are less expensive than pure color diamonds.

In essence, as the blue diamond’s color intensity and carat weight increases, its value greatly extends beyond $100,000, 200,000, or even more.  Generally speaking, blue diamonds are more expensive than other fancy colored diamonds except those with the red hue.

Join us as we explore the secrets behind the high prices of the most famous, coveted blue gemstones. In this article, you’ll learn why natural blue diamonds are a target for jewelers, collectors, investors and enthusiasts from all parts of the globe. Without much ado, let’s hit the ground running…

What Is a Blue Diamond?

What Is a Blue Diamond
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A blue diamond is a real, naturally occurring diamond with a vibrant blue tone. The blue diamond’s color results from the presence of boron traces within the pure diamond’s carbon structure. The concentration of boron molecules enables the diamond to absorb yellow light and reflect blue light in various hues.

Natural blue diamonds range in color from light blue, soft sky hues to more vibrant, deep blue ocean hues. However, you may still find a blue diamond with secondary hues like green, gray, or violet. You’ll want to know that these gemstones are not color-treated or enhanced to achieve the blue coloring – it is formed naturally beneath the earth’s surface.

You shouldn’t confuse the natural blue diamonds with real sapphires. While both gemstones are blue in color, they’re completely different. Unlike blue diamonds, sapphires are gemstones that fall in the corundum family. They usually contain traces of chromium, iron, titanium, copper and magnesium.

Natural blue diamonds are extremely rare, typically making up only 0.02% of all mined diamonds. These stones are found only in three mines in the world, including the Cullinan mine in South Africa, the Golconda mine in India, and the Argyle mine in Australia.

How Is a Blue Diamond Priced?

How Is a Blue Diamond Priced
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The pricing of diamonds – whether colorless or fancy colored ones – follows the four key parameters known as the 4C’s of grading diamonds:

The Cut

The diamond cut is a crucial factor for assessing the value of rare and natural gems like blue diamonds. Blue diamonds should receive cuts that enhance their color. The more uniformly distributed the blue hue, the higher the price of a genuine blue diamond per carat.

The size and shape of the cut also have a great influence on the color appearance of a blue diamond. Fancy-diamond shapes are known to intensify the blue color and raise the price even more. As a result, blue diamonds may be cut as heart, pear, oval, or trillion.

The Carat Weight

Since natural blue diamonds are particularly rare, their price per carat will increase exponentially for stones of larger sizes. You may need to shell out a six-digit price for a 1-carat natural gem with a vivid blue color.

Be that as it may, it’s difficult to give a fixed price for the stones of this color given that prices vary based on several factors. The table below provides the approximate cost of a blue diamond per carat:


Carat Weight (CT)


 Price Per Carat (in USD)
0.25 ct. From $1,700 to $2,500
0.50 ct. From $3,700 to $6,050
0.75 ct. From $5,050 to $8,300
1.00 ct. From $6,800 to $11,200
1.25 ct. From $8,000 to $12,000
1.50 ct. From $10,000 to $35,000
1.75 ct. From $16,000 to $55,000
2.00 ct. From $20,000 to $60,000 or more

Basically, natural blue diamonds are considered precious. For example, rings with round blue diamonds or blue emerald-cut engagement rings are exceedingly expensive and rare to find. For that reason, these stone aren’t used in ordinary jewelry but are a more preferred option for antique pieces, such as antique engagement rings.

They may also be used for earrings and necklaces. We’ve seen a lot of people place orders for earrings with blue diamonds. The problem is, finding two similar-sized blue diamonds for earrings is not a walk in the park.

You’ll need to find an expert source with international connections to help you search the right size and intensity for your blue diamond earrings. If you decide to search each jewelry store without any expert by your side, it will be a tall order. Besides, finding the right blue diamond at the best value is easier said than done.

The Color

The color intensity level refers to the strength of a diamond’s color. According to the GIA, there are three components that form the actual color of a diamond: hue, saturation and tone.

  • Hue – represents the dominant color of a diamond, which is blue in this case. If there are multiple colors, the dominant hue will appear last in the official certificate.
  • Tone – represents the extent in which light can penetrate into the fancy colored diamond, and consequently, how it affects the dominant color. For blue diamonds, the levels of tone are graded as follows – Faint Blue, Very Light Blue, Light Blue, Fancy Light Blue, Fancy Blue, Fancy Intense Blue, Fancy Deep Blue and Fancy Vivid Blue.
  • Saturation – represents how strong and intense the color is. The stronger and more vivid the color, the rarer the gemstone. As a result, the price goes up. Blue diamonds have a fairly narrow intensity range compared to other fancy colored diamonds, but their tone range is rather wide.

A pure blue diamond without a secondary modifier is hard to obtain, and thus more valuable. However, some color combinations – such as green-blue and gray-blue – are quite stunning. For example, check out this  0.46 Carat Fancy Gray Blue diamond and see how exceptional it looks.

In a nutshell, a pure blue diamond is considered most beautiful and valuable if it’s devoid of a secondary color. Even so, a pure blue diamond of light color might be considered less appealing and valuable than a gray-blue or green-blue diamond with a more vivid color

The Clarity

With fancy color diamonds, the dominant color plays a significant role in determining the gem’s value. But, given that natural blue diamonds are rarely occurring, even high-quality specimens will contain a bit of inclusions.

Of course, numerous inclusions can lower a blue diamond’s value by preventing the gem from revealing its true beauty and transparency. They may also threaten the gem’s durability in the long run.

Nonetheless, small inclusions won’t have any significant effect on the diamond’s clarity grading. Furthermore, even diamonds with numerous inclusions that lead to a low clarity grade are prized by connoisseurs if they exhibit an attractive face-up color.

Which Are the Most Expensive Blue Diamonds Ever?

The most expensive blue diamonds are quite rare. Each one of them is unique in terms of hue, carat weight, clarity and value. Here are some of the most expensive blue diamonds in the world:

The Hope Diamond – $250 million

The Hope Diamond - $250 million

The Hope Diamond is a fancy-dark, grayish-blue VS1 diamond with up to 45.52 carats. This blue diamond is one of a kind in the world. In 1958 when Harry Winston donated this diamond to the Smithsonian, he sent it via Registered Mail. The diamond is valued at $250 million.

The Heart Of Eternity – $80 million

The Heart Of Eternity - $80 million

The Heart Of Eternity is a fancy vivid blue diamond containing 27.64 carats. The gem was launched in January 2000 at London’s Millennium Dome and later unveiled at the Smithsonian. It is estimated to be more than $3 million per carat, or slightly over $80 million.

Wittelsbach-Graff -$80 million

Wittelsbach-Graff -$80 million

The Wittelsbach is a fancy deep-blue, internally flawless diamond with 31.06 carats. It initially had 35.56 carats. But when Graff bought it in 2008, he promptly recut it to enhance its color and brilliance. Today, the Wittelsbach blue diamond is estimated at $80 million.

The Imperial Blue – $79 million

The Imperial Blue - $79 million

With a total of 39.31 carats, the Imperial Blue remains the world’s biggest known flawless fancy deep blue diamond. It may not have the provenance and color intensity of other expensive blue diamonds, but its size speaks for itself. Acquired by Graff in 1984, the diamond commands at least $2 million per carat, equivalent to about $79 million.

The Blue Heart -$61 million

The Blue Heart -$61 million

The Blue Heart is a fancy deep blue, VS2 diamond with about 30.62 carats. Discovered in South Africa’s Premier Mine in 1908, this blue diamond has had several owners, including Marjorie Merriweather and Harry Winston. Based on current blue diamond prices, the Blue Heart is estimated at $61 million.


Due to the dwindling supply and increasing demand, genuine blue diamonds are some of the most expensive diamonds in the Fancy Color Diamond market. Their prices grow each year in record-breaking increments, so they may only be available for folks with deep pockets.

The blue diamond stones’ rarity, symbolism and value make them an excellent choice among investors, jewelers and collectors looking to capitalize on them. As far as blue gems go, a natural blue diamond really makes a statement.

When shopping for a blue diamond, you’ll want to ensure that you’re getting the best bang for your buck. Therefore, we strongly recommend buying this beautiful and mysterious gem from a reputable vendor, such as Leibish & Co or James Allen. These vendors offer the best prices coupled with a high level of expertise when pairing the diamond with a jewelry setting.

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