The Complete Guide to Natural Blue Diamonds (Updated 2025)

Natural blue diamonds are among the rarest and most captivating natural color diamonds. Their scarcity has only increased over time, with the closure of significant mines like the one in South Africa, which produced some of the purest sky-blue diamonds. Today, these mesmerising gems remain a symbol of unparalleled beauty and luxury.

5 Things to Know About Natural Blue Diamonds

• Boron atoms within the diamond's crystal structure are responsible for the blue hue, absorbing red, yellow, and green light to reflect a striking blue color.
• Natural blue diamonds are incredibly rare, with only one in every 200,000 diamonds mined classified as blue.
• Blue diamonds are Type IIb diamonds, making them excellent electrical conductors due to their boron content.
• The Hope Diamond, one of the most famous blue diamonds, is renowned for its deep blue color and storied history.
• Pure blue diamonds are rare, and many feature secondary hues such as grey or green, which can influence their value.

Looking to review our range of blue diamonds? View our natural blue diamonds for sale to find your perfect piece.

The Diversity of Blue Diamonds

Blue diamonds vary widely in hue, tone, and saturation ranging from very delicate  light blue to intense, deep ocean blue hues. Those from the now-closed South African mines often displayed a subtle, soft sky-blue hue, while the Argyle mine in Australia produced darker blue diamonds with a metallic or steel-like appearance. Some Argyle blue diamonds even feature violet undertones, creating an extraordinary and highly sought-after color combination.

The most prized stones exhibit a rich, saturated color reminiscent of the deep sea. Some blue diamonds may also display secondary hues, such as gray, violet, or green undertones, which can affect their overall value and appeal.

Our collection features a variety of blue diamond shades, including Turquoise, Violet, Indigo, Blue, Sky, and Steel. Each shade offers a unique visual experience, providing our clients with a range of options to match their personal style and preferences. From the tranquil tones of Sky blue to the intense depth of Steel blue, our selection caters to diverse tastes and desires.

Famous Blue Diamonds and Their Stories

Blue diamonds have long been treasured for their rarity and beauty. Some notable examples include:

The Hope Diamond: A Legendary Blue Gem

The Hope Diamond, weighing 45.52 carats, is one of the most famous blue diamonds in the world. Its remarkable deep blue hue and storied past—linked to royalty, mystery, and even superstition—make it an enduring symbol of intrigue and luxury. Today, it resides in the Smithsonian Institution, captivating visitors with its brilliance.

The Blue Moon of Josephine

Discovered in South Africa, the Blue Moon of Josephine is a Fancy Vivid Blue diamond weighing 12.03 carats. This flawless gem achieved global fame in 2015 when it was sold at auction for $48.4 million, setting a record for the highest price per carat of any diamond at the time.

The Okavango Blue

The Okavango Blue is a rare 20.46-carat Fancy Deep Blue diamond from Botswana. Its exceptional clarity and deep color make it one of the most significant blue diamonds discovered in recent years.

Tips for Buying Blue Diamonds

Understand the 4 Cs

When purchasing a blue diamond, consider the 4 Cs—color, clarity, cut, and carat weight—with particular emphasis on color:

• Color: The intensity of a blue diamond's color is the primary factor in determining its value. Generally, the more vivid and saturated the blue, the more valuable the diamond. Fancy Vivid blue diamonds command the highest prices due to their exceptional rarity and beauty. Look for a vivid and evenly distributed blue hue. Pure blue diamonds command the highest prices, while stones with secondary hues (e.g., grey or green) may be more affordable.
• Clarity: While color is the most crucial factor for blue diamonds, clarity and cut still play important roles in a stone's overall value and appearance. A well-cut blue diamond will maximize its color and brilliance. Opt for a clarity grade that balances quality and budget.
• Cut: Fancy cuts like radiant, cushion, or pear enhance the diamond’s color intensity and brilliance.
• Carat: Larger blue diamonds are exceedingly rare and valuable, so carat weight significantly impacts price.

Blue Diamond Jewellery Inspiration

Blue Diamond Tension Set Ring

This elegant ring features a natural diamond set in platinum, creating a timeless and sophisticated look.

Blue Diamond Halo Pendant

0.15 carat oval indigo blue diamond from the Argyle mine in Australia, tension set in an elegant 18K white gold ring

Vivid Blue Diamond Earrings

A stunning Fancy Vivid Blue diamond flanked by two smaller white diamonds, set in yellow gold for a bold yet harmonious design.

A stunning pair of 18k white gold stud earrings set with two natural Blue diamonds of 0.05 carat each. The simplicity of the setting allows the Blue diamonds to shine.

FAQs

Are blue diamonds real diamonds?

Yes, blue diamonds are natural diamonds formed with a blue hue due to the presence of boron atoms in their crystal structure.

Are blue diamonds valuable?

Blue diamonds are among the most valuable diamonds, with Fancy Vivid Blue and Fancy Intense Blue grades commanding the highest prices due to their rarity and brilliance.

What is the difference between sky blue and steel blue diamonds?

Sky blue diamonds are lighter and more delicate in hue, often from South African mines, while steel blue diamonds are darker with a metallic appearance, commonly sourced from the Argyle mine.

How should I care for blue diamond jewellery?

Clean your blue diamond jewellery with mild soap and water, avoid harsh chemicals, and store it separately to prevent scratches.

Can blue diamonds be used for engagement rings?

Absolutely! Blue diamonds make stunning and unique choices for engagement rings, offering a bold and luxurious alternative to traditional white diamonds.

Explore Langerman’s collection of natural blue diamonds to find your perfect piece.