Black diamonds are some of the rarest and most sought-after diamonds in the world. But what exactly makes certain black diamonds so exceptionally rare? In this article, we’ll examine the unique characteristics that make some black diamonds stand out as the rarest of the rare.
What Makes Black Diamonds Rare?
To understand what makes certain black diamonds so exceptionally rare, it’s important to first understand what makes all natural black diamonds rare. Black diamonds get their dark color from inclusions of graphite throughout the stone. This gives them a very deep, dark black appearance unlike any other diamond color. Less than 1% of all mined diamonds are natural black diamonds, making them far more rare than even more desirable colors like colorless or pink.
Additionally, black diamonds need to be cut more carefully than other diamonds to allow the maximum amount of light to be absorbed, enhancing their blackness. So not only do black diamonds occur more rarely in nature, but extra care and expertise is required in cutting and polishing them.
What Are Carbonados?
Carbonados are one specific type of natural black diamond that stands out as exceptionally rare. Unlike most other diamonds, carbonados are not formed underground due to immense heat and pressure. Instead, they are thought to have origins from extraterrestrial impacts of meteorites or asteroids hitting Earth. This gives them a very different chemical structure from other diamonds.
Carbonados contain pores and inclusions unlike normal diamonds. They also have unusually large crystal sizes. Their extraterrestrial origins mean carbonados make up only 2% of commercially available natural black diamonds. This makes them 100 times more rare than even standard black diamonds, which already rank among the rarest diamond colors.
Where Are Carbonados Found?
The main sources of natural carbonado diamonds are limited to just two regions in the world:
- Central African Republic
- Brazil
These two areas contain ancient cratons, ancient and stable portions of Earth’s crust. It is theorized that these cratons suffered massive meteorite impacts billions of years ago that produced the carbonados found there today.
No carbonado diamond deposits have been found anywhere else in the world. And the supply coming from the Central African Republic and Brazil is very limited. This further restricts the availability of these extremely rare black diamonds.
What Are Black Diamond Inclusions?
Natural black diamonds can also display special inclusions that increase their rarity and value. Some of the most desirable inclusions found in valuable black diamonds include:
| Inclusion | Description |
|---|---|
| Graphite | Layers or clusters of graphite inside the diamond giving it a black color |
| Garnets | Tiny red garnets visible inside when viewed under magnification |
| Hematite | A type of iron oxide mineral causing dark inclusions |
Black diamonds with visually striking and colorful inclusions of graphite or garnets are especially prized by collectors. Their unusual look increases the value and rarity.
What Are Carbonados Worth?
So how much do these incredibly rare carbonado black diamonds cost? Because of their rarity, carbonados can sell for prices exceeding $2,000 per carat. The exact value depends on the specific diamond’s size, quality, and visual appeal. But in general, they are valued at 100-200 times more than normal black diamonds.
In 2017, a 555-carat carbonado diamond found in the Central African Republic was valued at a price of $6 million. At $10,000+ per carat, it displayed the incredible value placed on these ultra-rare black diamonds.
To put the value in perspective, large and flawless colorless or white diamonds sell for $2,000-$4,000 per carat on average at auction. So carbonados can exceeded the per-carat value of even the most coveted white diamonds by 5-10 times or more.
Famous Carbonado Diamonds
Some of the most famous carbonado diamond specimens include:
- Sergio – At 3,167 carats, it is the largest carbonado diamond ever found, discovered in Bahia, Brazil in 1895.
- Amsterdam – Weighing 33.74 carats, it is a beautifully symmetrical pear-shaped carbonado, now on display in Amsterdam.
- Spirit of de Grisogono – At 312.24 carats, it is the world’s largest cut and polished black diamond, and was set into a ring.
These and other legendary carbonado diamonds represent the pinnacle of rarity and value among black diamonds. They are considered some of the rarest diamonds in the world.
Are Carbonados the Rarest Gemstone?
Carbonados are undoubtedly among the rarest diamond varieties. But how do they compare to other ultra-rare gemstones in terms of rarity?
Red diamonds and Jadeite are two other contenders for the rarest gemstone title. There are fewer than 20 known natural red diamonds over 5 carats in the world, making them impossibly scarce. And imperial green jadeite is produced in extremely small quantities, with just a handful of mines worldwide.
Overall, many experts still consider carbonados to be the absolute rarest gemstone variety in the world. With only two very limited geographic sources, unusual extraterrestrial origins, and possessing one-of-a-kind black color, carbonados stand in a league of their own when it comes to natural rarity.
Conclusion
Carbonado diamonds possess a combination of qualities that place them at the pinnacle of rarity, uniqueness, and value. Formed extraterrestrially eons ago, found in only two remote regions, with impossible-to-replicate black color and crystal patterns, carbonados represent the apex of natural diamond rarity. For diamond collectors, carbonados are the ultimate treasure – a chance to own one of the rarest substances on Earth.