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Are there black diamonds?

Yes, black diamonds do exist. They are a natural type of diamond that has a dark color due to the presence of inclusions and impurities in the stone’s composition. Black diamonds are quite rare and make up only a small percentage of diamonds found in nature. Let’s take a closer look at what black diamonds are, where they come from, and what makes them different from other diamonds.

What are black diamonds?

Black diamonds, also known as carbonado diamonds, are a natural type of diamond that has a dark black color. The dark color is due to the presence of graphite and other mineral inclusions in the stone’s composition. These inclusions absorb light and give the diamonds their black or dark gray color. The inclusions make the diamonds appear opaque rather than transparent like most other diamonds.

Black diamonds rank among the rarest diamonds in the world, accounting for only 2% of naturally occurring diamonds. They differ from most other diamonds not only in their dark color but also in their structure. Black diamonds have a porous, fibrous structure rather than the crystalline structure seen in clear diamonds. This gives black diamonds more of a matte appearance compared to the sparkling brilliance of clear diamonds.

Where do black diamonds come from?

Black diamonds have only been found naturally in two places in the world – Brazil and the Central African Republic. The conditions that allow for the formation of natural black diamonds are extremely rare. Black diamonds are believed to have formed 2-3 billion years ago deep within the Earth’s crust under high pressure and temperature conditions. They were brought close to the surface by volcanic eruptions.

The high content of inclusions is believed to be due to the diamonds forming in contact with the ancient ocean floor. As the magma from volcanic eruptions carried the diamonds upward, bits of organic materials and other minerals were trapped inside the growing crystal structure, resulting in black diamonds with their characteristic dark color and porous texture.

How are black diamonds formed?

Natural black diamonds form through a complex combination of geological conditions deep within the Earth’s crust. Here are the key factors in their formation:

  • Exposure to primordial carbon-rich fluids – Black diamonds formed from primordial fluids in the mantle that were rich in carbon and other dark minerals.
  • High pressure – Natural diamonds require extremely high pressure, above 45,000 psi, to crystallize. Black diamonds formed 150-200 km below the surface.
  • High temperature – In addition to pressure, temperatures exceeding 2,000°F are needed to crystallize diamonds.
  • Rapid ascent to surface – The volcanic eruptions that carried black diamonds upward happened quickly, preventing the diamonds from being destroyed on their journey.

It is this specific combination of ancient carbon-rich fluids, immense heat and pressure, and rapid volcanic transport that created the unique conditions for black diamond formation billions of years ago. Modern synthetic black diamonds can be created in the lab, but natural black diamonds can only occur under these precise primordial conditions deep underground.

What causes the black color in black diamonds?

The dark black color of black diamonds is caused by the high concentration of inclusions and impurities present in the stones. Some of the key factors leading to the black color include:

  • Graphite – Tiny graphite crystal clusters are common inclusions giving black diamonds their color.
  • Hydrogen – Hydrogen impurities in the diamond structure also contribute to the black color.
  • Carbon/mineral deposits – Bits of carbon, organic matter, and other minerals trapped in the stone during formation add to the black color.
  • Plastic deformation – Structural deformation and resulting dislocations in the crystal lattice distort light absorption.

Additionally, the porous, fibrous structure of black diamonds causes more light to be absorbed rather than reflected back, enhancing their opaque black appearance. The more saturated and intense the black color, the higher quality a black diamond is considered.

Do black diamonds sparkle?

No, black diamonds do not sparkle like clear diamonds. The inclusions and impurities that give black diamonds their dark color also prevent them from exhibiting the brilliant sparkle that clear diamonds are prized for. The porous structure scatters light rather than allowing light to refract and reflect off the crystalline facets. This gives black diamonds more of a matte, opaque appearance.

Additionally, the cut of a black diamond is designed to enhance the color rather than enable light reflection and refraction. Black diamonds are most commonly cut into round brilliant shapes. The shallow facets accentuate the saturation of the black color rather than creating sparkle. So while black diamonds have their own distinctive beauty, they do not possess the dazzling sparkle of clear diamonds.

Are black diamonds expensive?

Black diamonds are considerably more expensive than clear diamonds. Their rarity makes natural black diamonds some of the most expensive diamond types. High quality black diamonds over 1 carat can cost over $4,000 per carat. The price increases exponentially for larger stone sizes. A 5 carat black diamond could cost over $20,000.

The intensity of the black color also impacts the price. Completely opaque, jet black diamonds with no gray undertones are the most desirable and therefore the most expensive. In general, the richer and more saturated the black, the higher the value of the diamond. Inclusions and blemishes actually increase rather than detract from the value of black diamonds since they enhance the black color.

How are black diamonds graded?

Black diamonds cannot be graded using the standard diamond grading scale for color and clarity. Instead, black diamonds are evaluated based on the intensity and purity of their black color. The Black Diamond Spectrum was established specifically for grading the darkness of black diamonds.

The spectrum ranges from light gray (N1) to pure black (N10). Most black diamonds on the market fall between N3 to N7 on the spectrum. The highest grade N10 black diamonds are extremely rare and valuable. Black diamonds are also assessed for outstanding inclusions that add artistic allure to the stone.

Black Diamond Color Spectrum

Color Grade Color Description
N1 Dark Gray
N2 Grayish Black
N3 Dark Charcoal
N4 Jet Black
N5-N10 Intense Black

How should black diamonds be cared for?

Black diamonds require special care compared to other diamond types. Here are some tips for keeping black diamonds looking their best:

  • Avoid ultrasonic cleaning – The cavities and inclusions can trap cleaning solutions.
  • Clean with soapy water – Use a soft brush and mild soap to gently scrub the diamond.
  • Protect from sharp blows – The fibrous structure is vulnerable to fracture and chipping.
  • Check settings regularly – Make sure prongs and bezels are secure to avoid loss of stones.
  • Keep away from chemicals – Avoid bleach, acids, and hydrogen peroxide which can damage the surface.

Storing black diamonds separately in a padded container will help protect them from damage. Regular cleaning and inspection by a jeweler is recommended to ensure black diamonds retain their beauty and value over time.

What jewelry is black diamonds best suited for?

Black diamonds make striking center stones for engagement rings, pendants, and earrings due to their mystique and allure. Their darker color also makes black diamonds suitable for men’s jewelry such as masculine rings. Smaller black diamonds are often used as accent stones paired with clear white diamonds for contrast.

Black diamonds should be set in protective styles like bezels and halo settings. This protects the vulnerable girdle area prone to chipping. The contrast of black diamonds against white metal like platinum and white gold is particularly striking. Black diamonds also suit darker metals like yellow gold and rose gold for a coordinated designer look.

Are black diamonds ethical?

Natural black diamonds are considered conflict-free and ethically sourced. Almost all black diamonds on the market today come from the two original source countries Brazil and the Central African Republic. Black diamonds mined from these locations have not been associated with unethical practices.

However, some lab-created black diamonds are produced using questionable manufacturing methods. Consumers should check for independent ethical certification from organizations like the GIA when purchasing black diamonds, especially simulated diamonds. This ensures black diamonds are procured in an ethical manner.

Should I buy black diamonds?

Black diamonds offer a unique alternative to more common clear white diamonds. Their exotic beauty and rarity make them intriguing choices for jewelry. However, black diamonds do require special care and settings to stay secure and undamaged. Keep these pros and cons in mind when deciding if black diamonds are the right choice:

  • Pros: Rare and unique, high value retention, distinctive color, conflict-free
  • Cons: Expensive, prone to fragility, limited cut shapes and sparkle

For buyers drawn to their striking aesthetics, black diamonds can be an alluring jewelry choice. As long as their special vulnerabilities are accounted for, black diamonds make one-of-a-kind additions to fine jewelry collections. Their scarcity ensures black diamonds will always intrigue collectors and jewelers alike.


Black diamonds are real natural diamonds that have an exotic black or dark gray color. They are some of the rarest diamonds in the world, formed under ancient conditions deep in the Earth. The black color comes from inclusions like graphite and carbon deposits that absorb light. Black diamonds do not sparkle but have a rich, opaque appearance. Their rarity and intense color make them more valuable than clear diamonds. With special care, black diamonds can make distinctive statement pieces in fine jewelry.