When people search for Carbonado, they want answers. They want to understand what makes this black diamond so different from traditional diamonds, whether it is valuable, how it forms, and why its origins are still debated. Carbonado sits in a class of its own. It is mysterious, scientifically fascinating, and visually bold. As a jeweller who loves unconventional materials, I can say Carbonado is one of the most intriguing gems on Earth.
What is Carbonado?
Carbonado is a polycrystalline form of diamond (also known as black diamond) made up of tiny diamond crystals fused. Unlike traditional gemstones, Carbonado is opaque, usually charcoal black or deep brown, with a porous texture that feels almost metallic. It is far tougher than standard diamond, which is already the hardest natural substance known. This toughness comes from its interlocking structure, giving it exceptional resistance to impact.
It is also electrically conductive, unlike most diamonds. This makes Carbonado useful beyond jewellery, particularly in industry. Its conductivity and durability give it a unique identity, bridging beauty and function. Carbonado is not a stone that sparkles classically, but it has an understated, powerful presence that makes it striking in modern jewellery.
Carbonado’s unusual appearance and extreme durability make it perfect for bold, sculptural designs. While faceting is uncommon, polished pieces and geometric cuts showcase its character beautifully.
Key points:
• Carbonado is a polycrystalline black diamond with exceptional toughness.
• It is electrically conductive and visually distinct from traditional diamonds.
How Does Carbonado Form?
Carbonado does not form through the same volcanic processes as typical diamonds. Instead, its structure suggests a much more unusual origin. The lack of inclusions commonly seen in diamonds, along with the presence of trace elements like hydrogen and nitrogen in unusual ratios, points to a formation process outside the Earth’s mantle.
Studies show that Carbonado has a porous texture, very different from normal diamonds. These pores sometimes contain organic carbon, which raises fascinating questions about its past. Carbonado also contains small amounts of minerals not usually associated with Earth-formed diamonds, adding weight to theories of extraterrestrial influence.
The formation of Carbonado remains one of the biggest geological mysteries in gemmology. While theories vary, what is certain is that its structure cannot be explained by typical diamond growth models.
Key points:
• Carbonado does not form through normal diamond processes.
• Chemical signatures suggest an unusual and possibly extraterrestrial origin.
Where is Carbonado Found?
Carbonado is found exclusively in two locations: Brazil and the Central African Republic. This limited distribution is one of its most intriguing aspects. Both regions sit on opposite sides of the South Atlantic, yet the deposits share identical properties. This connection has led many researchers to propose that Carbonado predates the separation of the South American and African continents.
No Carbonado diamonds have ever been found in traditional diamond-bearing volcanic pipes, which adds to the mystery. Instead, they occur in sedimentary deposits, suggesting they may have arrived from elsewhere before settling in these regions.
Because the material does not appear in kimberlite or lamproite (the main diamond host rocks), Carbonado stands apart as a geological anomaly. Its rarity and concentrated distribution keep it firmly in the category of unusual collector material.
Key points:
• Carbonado is found only in Brazil and the Central African Republic.
• Its distribution suggests an origin that predates continental separation.
Carbonado Pricing
Carbonado pricing depends on size, colour uniformity, and structural integrity. Industrial-grade material is widely used for cutting tools due to its strength, often sold by weight rather than by individual piece. Jewellery-grade Carbonado, however, forms a smaller, more specialised market.
Polished Carbonado suitable for jewellery typically ranges from a few hundred to several thousand pounds, depending on quality and craftsmanship. Large, clean pieces over 5 carats are especially desirable and often command premium prices due to their limited availability.
Over the past decade, demand for black diamonds has risen significantly. Market studies show that sales of black diamond jewellery increased by around 25 percent between 2012 and 2022. Carbonado benefits from this trend, especially in contemporary design and men’s jewellery.
Key points:
• Jewellery-grade Carbonado ranges from hundreds to thousands of pounds.
• Demand for black diamond jewellery has risen by about 25 percent in ten years.
History of Carbonado
Carbonado was first identified in Brazil in the mid-19th century. At the time, its unusual appearance led miners to believe it was simply burnt diamond or an industrial byproduct. Only later did mineralogists confirm its unique structure.
During the late 19th and early 20th centuries, Carbonado became essential in the industrial world. Its toughness made it ideal for drill bits and grinding tools, particularly in mining and engineering. This association with industry meant Carbonado remained largely unknown to the jewellery world until recent decades.
As design preferences expanded and unconventional gemstones gained a following, Carbonado entered fine jewellery. Its bold, dark appearance appealed to modern designers who sought contrast and strength in their pieces. Today, Carbonado continues to attract interest from collectors, gemmologists, and jewellers alike.
Key points:
• Carbonado was first discovered in Brazil in the 1800s.
• Its toughness made it invaluable to industry long before jewellery adopted it.
Different Types of Carbonado
Unlike traditional diamonds, Carbonado does not come in a range of colours or clarity grades. All Carbonado is essentially opaque, with colours ranging from deep grey to jet black. What varies is density, porosity, and structural consistency.
Some Carbonado displays a more pronounced metallic sheen, while others have a matte finish. Pieces with fewer internal fractures are more desirable for cutting and jewellery. Very high-density Carbonado is often reserved for industrial applications due to its ability to withstand intense pressure.
Collectors sometimes differentiate between Brazilian Carbonado and African Carbonado, although scientifically, the materials are nearly identical. The interest lies more in provenance than physical distinction.
Key points:
• Carbonado varies in density and texture rather than colour or clarity.
• Brazilian and African material is similar, with value based mainly on provenance.
Can Carbonado Diamonds Be Made in a Lab?
Laboratory-grown black diamonds exist, but they are not Carbonado. They are typically treated or synthetic diamonds produced through high-pressure, high-temperature (HPHT) processes. Lab-grown black diamonds are solid-structure diamonds, not polycrystalline like true Carbonado.
Artificially creating Carbonado is difficult because its porous structure and unusual chemical composition are challenging to replicate. No commercial process successfully reproduces the natural Carbonado’s characteristics.
For collectors and jewellers, this is a positive point. It means that genuine Carbonado sold on the market is almost always natural, not synthetic or treated.
Key points:
• Lab-grown black diamonds exist, but they are not true Carbonado.
• Carbonado’s structure has not been replicated synthetically.
The Possible Origins of Carbonado Diamonds
Carbonado’s origins are one of the most debated subjects in gemmology. Several theories exist, each supported by compelling evidence:
One theory suggests Carbonado formed in supernova explosions before the early Solar System existed. The hydrogen-rich composition and porous structure align with materials known to form in space. According to this theory, Carbonado arrived on Earth via meteorites billions of years ago.
Another theory proposes that Carbonado formed in Earth’s crust during a period of intense geological activity. However, the lack of nitrogen aggregation typical of mantle-formed diamonds weakens this argument.
A third theory suggests asteroid impacts may have produced the extreme pressures needed for Carbonado formation, though this remains speculative. Despite decades of research, its origin remains unresolved, which only adds to its appeal.
Key points:
• The leading theory links Carbonado to supernova origins and meteorite impact.
• No single theory explains all its unusual characteristics.
Conclusion
Carbonado is a diamond like no other. It is tough, mysterious, and steeped in scientific intrigue. Whether you are drawn to its possible extraterrestrial past, its striking black appearance, or its rarity, Carbonado offers something no other gemstone can match. It stands at the crossroads of geology, history, and design, making it a favourite among modern jewellers and curious collectors. To hold a piece of Carbonado is to hold a fragment of the unknown, shaped by forces that science is still trying to understand.
FAQ
Is Carbonado the same as a black diamond?
Carbonado is a natural black diamond, but not all black diamonds are Carbonado.
Is Carbonado valuable?
Yes. Jewellery-grade Carbonado can be valuable, especially in larger sizes.
Can Carbonado be faceted?
It can, but its polycrystalline structure makes cutting more challenging.
Does Carbonado come from space?
Possibly. Many scientists support the theory of an extraterrestrial origin, but it is not confirmed.
Is Carbonado stronger than regular diamond?
It is tougher, meaning more resistant to breaking, though both share exceptional hardness.