The Rarest Diamond Color: What Tops the Scarcity Chart?

Last Updated on September 28, 2023 by Juli "Jewels" Church

Here's a fun fact: For every 10,000 colorless natural diamonds mined, only one natural colored diamond is discovered? That alone should give you a sense of the rarity we're talking about here.

rarest diamond color, red

This makes certain colored diamonds some of the most sought-after gemstones on Earth, fetching astronomical prices at auctions and becoming the stuff of legends.

What if I told you that even within this ultra-exclusive category, there exists a color so rare, that its existence defies the already minuscule odds? In this post, I will delve into the subject of the rarest diamond color, investigating the scientific phenomena that give rise to its hue and its eye-popping market value.

SPOILER ALERT: The rarest diamond color is red. This color is so rare that there are less than 30 true red diamonds in the world, and most of them are less than half a carat.

The Alchemy of Trace Elements and Structural Distortions

Diamonds, essentially crystallized carbon lattices, are not always the gleaming, transparent stones commonly imagined. There is a whole category of fancy colored diamonds that owe their colors to various factors, namely the presence of trace elements and structural distortions in their crystal lattice.

Trace elements, as the name suggests, are foreign atoms that replace some carbon atoms in a diamond's structure. For example, the presence of nitrogen leads to yellow and orange hues, while boron can create blue diamonds. These elements absorb specific wavelengths of light, reflecting the remaining spectrum and thereby creating the diamond's color.

On the other hand, structural distortions refer to irregularities in the arrangement of the carbon atoms within the crystal lattice. When such anomalies occur, they can change the way the diamond interacts with light, leading to unique shades. For instance, green diamonds owe their hue to the radiation they've been exposed to, which creates defects in the lattice.

The Most Common Diamond Colors

Brown and Yellow Diamonds

Brown and yellow diamonds are not just widely accessible; they're also incredibly versatile. These colored diamonds contain nitrogen atoms, which brings about a spectrum of shades, from the palest champagne to the richest cognac. The variations in hue make them adaptable to a multitude of jewelry styles—whether you're going for understated elegance or bohemian flair.

brown diamonds
canary yellow diamond

Though they're the most common diamond colors, their affordability shouldn't be mistaken for a lack of beauty or desirability. They offer a unique aesthetic that can be as eye-catching as it is accessible. So, while they may not command the stratospheric prices of their rarer counterparts, they certainly hold their own in the realm of precious stones.

Fancy White Diamonds

Fancy white diamonds offer a singular allure, distinct from the traditional transparent or colorless diamonds. While they appear milky-white, their ethereal hue doesn't arise merely from a lack of color. Instead, it's often the result of minute inclusions—tiny imperfections or foreign particles—that scatter light in a unique way. These microscopic elements, sometimes described as internal "clouds," give the diamond a diffuse, dreamlike appearance.

fancy white diamond

So fancy white diamonds serve as captivating paradoxes: they are diamonds whose value is elevated not in spite of their inclusions, but because of them. This makes them sought-after by collectors and connoisseurs

Black Diamonds

The allure of back diamonds lies in their enigmatic character. These gems defy the common notion that a diamond's worth is directly proportional to its clarity and absence of color. Rather than stemming solely from internal flaws or inclusions, the opaque blackness of these diamonds often comes from microscopic particles of graphite embedded within their structure. These graphite particles absorb most incoming light, imbuing the diamonds with an absorbing, velvety blackness.

leibish black diamond oval 4-69 ct

This lends them a unique aesthetic that is both mysterious and bold, appealing to those who desire something unconventional. In the world of gemstones, where brilliance and sparkle are often the most sought-after traits, black diamonds make a compelling case for the beauty of opacity and darkness.

Rarer Diamond Colors

Green Diamonds

Green diamonds are nature's own artisans, deriving their color not from trace elements but from the fascinating interaction with natural radiation over millions of years. The radiation causes specific lattice defects, which in turn manifest as varying shades of green.

Fancy Intense Yellow Green Diamond 2.02 ct

Because their hue is often skin-deep and localized to the surface, green diamonds offer a visual experience akin to holding a fragment of Earth's own timeline. Unlike other colored diamonds, each green diamond is a distinct product of its environment, making it a geological fingerprint of sorts.

Orange Diamonds

When it comes to orange diamonds, their vivid hue is nothing short of a spectacle. More than just colorful, these diamonds are an outcome of intricate geological processes involving nitrogen atoms and structural anomalies.

4.03 carat, Fancy Vivid Yellow Orange Diamond

This precise combination gives rise to diamonds with an arresting orange hue that can range from a delicate tangerine to a robust saffron. Their vibrant color captures the imagination and is ideal for those who seek a diamond that's both extremely rare and expressive.

Pink Diamonds

Pink diamonds are among the most romantic and desired in the world, and their allure lies in their unexpected color. Unlike other diamonds, which owe their hues to the presence of trace elements, pink diamonds acquire their color from distortions in their crystal lattice during their geological formation.

0.60 carat, Fancy Brown Pink Diamond, Pear Shape

These distortions manipulate the way pink diamonds absorb and reflect light, giving it their iconic shades of pink. From soft pastels to vibrant fuchsias, pink diamonds encapsulate a range of emotions, making them a poetic choice for significant milestones.

Blue Diamonds

Fancy blue diamonds are a study in celestial beauty. They owe their captivating shades, ranging from pale blue to deep azure, to the presence of trace amounts of boron in their crystal structure. The boron atoms alter the diamond's absorption spectrum, allowing only blue light to escape and resulting in their enchanting hue. The depth of the color can vary based on the concentration of boron, making each blue diamond a unique gem with its own distinct personality.

blue diamond

Blue diamonds are among the rarest diamonds, and their mesmerizing color makes them highly coveted in both the artistic and investment realms.

But the crown jewel, the epitome of rarity and the subject of our focus is, drumroll...

The Rarest Diamond Color: Red

There's something about the color red that irresistibly captures the human imagination. However, in the realm of diamonds, red isn't merely a hue; it is the zenith of rarity. As I've mentioned, less than 30 true red diamonds are known to exist, as in those without a secondary color like purple.

0.60 carat, Fancy Purplish Red Diamond, Radiant Shape

0.60-carat Fancy Purplish Red Diamond, costing around US$600K at Leibish & Co

The Science Behind Red Diamonds

So what makes a red diamond red? Unlike other colored diamonds, which get their color from trace elements like boron or nitrogen, red diamonds owe their coloration to an unusual phenomenon known as 'plastic deformation.' During the diamond's journey to the Earth's surface, immense pressure alters its atomic structure, distorting its crystal lattice in a way that selectively absorbs light.

This unique interaction with light causes the diamond to emanate a red hue. It's a complicated dance of physics and chemistry, resulting in a gemstone that can legitimately be described as one in a million.

fancy red diamond

Where Are Red Diamonds Found?

These elusive gems have been found scattered around the world, but most notably in Australia's Argyle mine, which ceased its operations in 2020. Brazil and Russia have also been graced with the occasional discovery of this scarlet marvel.

Famous Red Diamonds

Given their extreme scarcity, each red diamond carries its own set of legends and fascinating history. Among these fabled gems, a few stand out:

  • The Moussaieff Red Diamond: At 5.11 carats, this triangular marvel is the largest Fancy Red diamond ever graded by the GIA. Discovered by a Brazilian farmer and later acquired by Moussaieff Jewelers, it's a stone steeped in a lore as rich as its color.
  • The Rob Red Diamond: Although smaller at just 0.59 carats, the Rob Red is renowned for its intense and vivid red hue, often cited as the most saturated red diamond in existence.
  • The Hancock Red Diamond: This less-than-a-carat gem fetched an astonishing $926,000 at a 1987 auction, setting a world record for the price per carat.
  • The De Young Red: Initially mistaken for a garnet and sold in a flea market, this 5.03-carat gem now sits in the Smithsonian, exemplifying the enigmatic nature of red diamonds.

Understanding Rarity

Why Are Some Diamonds More Rare Than Others?

Diamond rarity is not just a haphazard game of geological luck; it's a complex interplay of several factors. First, let's consider the trace elements present during a diamond's formation. Elements like boron and nitrogen substitute themselves for carbon atoms in a diamond's lattice structure, altering the stone's color.

Secondly, structural distortions—variations in the geometric arrangement of the diamond's carbon atoms—can lead to uncommon hues. These distortions happen over hundreds of millions of years, impacted by seismic shifts and tectonic activity.

Lastly, the conditions under which a diamond forms—temperature, pressure, and time—also significantly impact its rarity. And let's not forget the sheer scarcity of finding one of these rare colors among the glut of more common diamonds.

The Price of Rarity

Rarity walks hand-in-hand with exclusivity, and nowhere is this principle more vividly illustrated than in the world of diamonds. Take red diamonds, the pinnacle of scarcity, for example. With fewer than 30 known to exist, their value soars to extraordinary heights—up to $1 million per carat. Such a figure isn't merely a price tag; it's a testament to the diamond's unparalleled standing in the realm of precious stones.

But how do red diamonds stack up against other colors in the price-per-carat metric? Let's delve into the comparative pricing landscape:

  • Red Diamonds: Up to $1 million per carat
  • Blue Diamonds: $600,000 to $800,000 per carat
  • Pink Diamonds: $300,000 to $500,000 per carat
  • Orange Diamonds: $100,000 to $200,000 per carat
  • Green Diamonds: $80,000 to $150,000 per carat
  • Fancy White Diamonds: $10,000 to $50,000 per carat
  • Black Diamonds: $2,000 to $5,000 per carat
  • Yellow and Brown Diamonds: $1,000 to $3,000 per carat

Grading Rarity: Going Beyond the 4 Cs

When it comes to diamond evaluation, you've probably heard of the 4 Cs: Carat, Cut, Clarity, and Color. But in the case of a colored diamond, grading Color isn't as straightforward as it seems.

When evaluating colored diamonds, the standard 4 Cs are not sufficient. Colored diamonds are assessed using a unique scale: the Fancy Color Diamond Grading system. This system goes beyond the 4 Cs to scrutinize three main attributes that characterize the diamond's true color: Hue, Tone, and Saturation.

  • Hue: This refers to the actual color of the diamond, such as blue, green, or red.
  • Tone: This represents the lightness or darkness of the color.
  • Saturation: This assesses how strong or weak the color appears.

For instance, a Fancy Vivid Blue diamond is not merely blue. It's a diamond with a deep, fully saturated blue hue, which is why it will typically be more expensive than a Fancy Light Blue diamond. These additional gradations in the Fancy Color Diamond Grading system allow for a far more nuanced and accurate evaluation of a colored diamond's worth.

Here are the different tiers for grading colored diamonds:

  • Faint
  • Very Light
  • Light
  • Fancy Light
  • Fancy
  • Fancy Dark
  • Fancy Intense
  • Fancy Deep
  • Fancy Vivid
GIA Colored Diamonds Color Reference Charts

Grading chart for tones and saturations of pink diamonds.

Final Spark of Insight

We've embarked on an illuminating exploration of colored diamonds, each with its own unique blend of allure and scientific marvel. Yet, it's the rarest diamond colors—red, blue, and pink—that truly defy the odds, standing as dazzling anomalies in an already exclusive world. Owning one of these extraordinarily rare diamonds is like holding a key to one of Earth's most enigmatic secrets. 

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