The largest cut diamond in the world, the Cullinan I, also known as the Great Star of Africa, remains one of the most astonishing achievements in gemcraft. Weighing in at 530.2 carats, this D color, VVS1 clarity diamond anchors the Crown Jewels of the United Kingdom as a symbol of both natural rarity and human mastery.
Below, we explore its specifications, history, valuation, cutting process, and care, using a structured data table and detailed sections to highlight what makes this stone extraordinary.
| Stone | Carats | Color Grade | Clarity |
|---|---|---|---|
| Cullinan I (Great Star of Africa) | 530.20 | D | VVS1 |
| Cullinan II (Lesser Star of Africa) | 317.40 | D | VS2 |
| Cullinan Diamond (Rough) | 3106 | D | vs |
Historical Journey of the Cullinan Diamond
Discovered in 1905 at the Premier Mine in Cullinan, South Africa, the original crystal weighed over 3,100 carats. It was bought by the Transvaal government and gifted to King Edward VII, who entrusted the renowned Dutch cutter Joseph Asscher with dividing and polishing the fragments. The result included the Cullinan I and Cullinan II, which entered the Crown Jewels and remain central to British ceremonial regalia.
Cutting Process and Precision
Asscher studied the stone for weeks before making a single decisive cleave. The rough diamond split along a natural fracture plane, revealing smaller workable pieces. Each cut facet was planned to maximize size, clarity, and brilliance, turning a singular crystal into multiple legendary stones. The precision of those early decisions continues to influence how light performs within the finished gems.
Specifications and Valuation
Experts evaluate the largest cut diamond using the Four Cs, origin, and historical pedigree. Its D color places it at the top of the color scale, while VVS1 clarity indicates minute inclusions only visible under 10x magnification. When adjusted for size, color, and clarity, auction estimates for comparable quality can reach tens of millions of dollars, though the stone itself remains part of the inalienable Crown Jewels.
Modern Display and Preservation
Today, the Cullinan I rests in the Imperial State Crown, showcased under controlled conditions in the Jewel House at the Tower of London. Low-temperature lighting, humidity regulation, and restricted access protect the stone from thermal stress and abrasion. Continuous monitoring ensures that any change in appearance or integrity is detected immediately.
Key Takeaways
- Largest cut diamond is Cullinan I at 530.2 carats, D color, VVS1 clarity
- Part of the United Kingdom Crown Jewels, mounted in the Imperial State Crown
- Cut by Joseph Asscher in 1905–1906 using a single precise cleave
- Valued in the tens of millions, reflecting rarity, color, and history
- Protected by strict environmental controls at the Tower of London
FAQ
Reader questions
How was the Cullinan diamond discovered and who owned it originally?
It was found in 1905 at the Premier Mine in Cullinan, South Africa, purchased by the Transvaal government, and gifted to King Edward VII.
Who cut the Cullinan I and Cullinan II, and how long did it take?
Joseph Asscher cut both stones after weeks of analysis; the entire process from cleaving to polishing spanned about eight months.
Where are the Cullinan I and Cullinan II currently located?
Both are set in the Crown Jewels of the United Kingdom, with Cullinan I in the Imperial State Crown and Cullinan II in the Imperial State Crown.
What would be the estimated value if the Cullinan I were to appear on the open market today?
Experts suggest a value in the tens of millions of dollars, adjusted for size, color, clarity, and provenance, though it is not available for sale.