What Is the Biggest Diamond in the World
The biggest diamond ever discovered is the Cullinan, a 3106 carats rough stone found in South Africa in 1905, and it remains the largest gem-quality rough diamond on record source. The stone was named after Sir Thomas Cullinan, the chairman of the Premier Mine, and it was purchased by the Transvaal colonial government before being presented to King Edward VII.
In terms of polished weight, the largest clear diamond cut from the Cullinan is the Great Star of Africa, also called Cullinan I, at 530.2 carats, making it the biggest clear polished diamond in the world source. The second-largest polished piece from the same rough is the Second Star of Africa, or Cullinan II, at 317.4 carats, and both stones are part of the British Crown Jewels.
How Big Is the Cullinan Diamond in Physical Size
The Cullinan rough was about the size of a human fist, measuring roughly 100 millimeters in length and weighing over 620 grams, which is more than 1.3 pounds source. Its extraordinary size and lack of visible flaws made it exceptional for cutting, even though the rough had to be split carefully to maximize the yield of large gemstones.
When the Cullinan was cleaved and polished, it produced several major stones and many smaller brilliant-cut gems, with the largest pieces graded as colorless and internally flawless source. The cutting process, led by Joseph Asscher and Company, took months of planning and precise execution to preserve the diamond's clarity and size.
How the Biggest Diamond Compares to Other Large Diamonds
Largest Diamonds Ever Found
Other famous large diamonds include the Lesedi La Rona at 1109 carats rough, found in Botswana in 2015, and the Excelsior Diamond, which weighed 995 carats before being cut into many smaller stones source. While these stones are large, the Cullinan remains the biggest single gem-quality rough diamond ever recovered.
Current Large Diamond Discoveries
More recent finds, such as the 1174 carats Sewelo rough uncovered in Botswana in 2019 and the 1484 carats Lesotho Legend discovered in 2018, are large but still smaller than the Cullinan source. These stones are typically sold to major cutting and polishing firms or auctioned through specialized houses, with prices driven by size, color, and clarity.
Polished Diamonds and Market Value
The largest polished diamonds from the Cullinan and other exceptional roughs are held in national collections or sold at high-profile auctions, where price per car