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rljewelers
November 20th, 2025
We just got our first peek at The Black Falcon, a 612.34-carat carbonado diamond now being billed as the largest cut diamond on Earth.

Black falcon3a

The dramatic, falcon-headed gem represents a once-unthinkable triumph in lapidary science — one that required seven years of experimentation, custom toolmaking and, at times, sheer stubbornness from master cutter Peter Herbosch of Antwerp.

The story begins in Guinea, where the rough stone was discovered in 2008. Weighing an extraordinary 887.22 carats, the black diamond confounded cutters for years. Carbonado diamonds — also known as black diamonds — are significantly tougher than conventional mined diamonds because they possess no cleavage planes, the structural “guidelines” cutters rely on to shape a diamond without shattering it.

Herbosch summarized the challenge bluntly in an interview with The Times of London: “You could grind it on traditional grinding wheels for years and wouldn’t even be able to tell.”

Unlike single-crystal diamonds, carbonados are polycrystalline aggregates — a microscopic mosaic of diamond, graphite and amorphous carbon. This structure makes them extraordinarily tough and nearly impossible to shape using conventional means.

To tackle the stone, Herbosch engineered his own diamond-edged grinding system and employed highly controlled laser techniques, slowly coaxing the gem into its final sculptural form. Its natural outline resembled a bird's profile, inspiring Herbosch to embrace the shape; the final result is a polished falcon’s head, part jewelry, part objet d’art, and wholly unprecedented.

The Black Falcon’s debut dethrones The Enigma, the 555.55-carat cut carbonado that held a Guinness World Record and sold for $4.3 million at Sotheby’s in 2022. It also surpasses the largest yellow-brown polished diamond, the 545.67-carat Golden Jubilee, and even the world-famous 530.2-carat Cullinan I, the largest colorless cut diamond. Yet none share the Black Falcon’s geological mystery.

Scientists believe carbonado diamonds are between 2.6 and 3.2 billion years old. They've been found mainly in Brazil and the Central African Republic — regions once connected on the prehistoric supercontinent — and their origin remains hotly debated. One theory proposes formation deep within Earth’s mantle under extreme conditions; another suggests they arrived via meteorites, formed in supernova shock waves before falling to Earth billions of years ago.

Their characteristic black color does not come from trace chemical impurities as with other fancy-colored diamonds, but from myriad internal inclusions — primarily graphite — and their light-absorbing polycrystalline structure.

Herbosch told The Times of London that he expects the stone could fetch €8 - €12 million ($9.2 - $13.8 million) given its scale, sculptural identity and scientific intrigue. Only time will tell.

Credit: Conceptual rendering of The Black Falcon diamond by The Jeweler Blog using ChatGPT and DALL·E 3.