A handful of diamonds are known by name, the way paintings are. Most were found in India before 1700 or in South Africa after 1870, most were cut and recut more than once, and nearly all of them are now in a crown, a museum or a vault. Here are the ones you are most likely to meet, with the figures as the museums and their owners give them.
Cullinan
The largest gem-quality rough diamond ever found: 3,106 carats, dug from the Premier mine near Pretoria in 1905 and named after the mine's chairman. The Transvaal government bought it and presented it to Edward VII. The Asscher firm in Amsterdam cleaved and cut it in 1908 into nine major stones and nearly a hundred small ones. Cullinan I, the Great Star of Africa, a pear of 530.2 carats, sits in the Sovereign's Sceptre; Cullinan II, the Lesser Star of Africa, a cushion of 317.4 carats, in the front of the Imperial State Crown. Both are in the Tower of London. Read more about Antwerp and Amsterdam as cutting cities.
Koh-i-Noor
"Mountain of light" in Persian. An Indian stone with a history that runs through Mughal emperors, Persian and Afghan rulers and the Sikh kingdom, before the East India Company handed it to Queen Victoria in 1849. Cut as an Indian rose of about 186 carats, it was recut in London in 1852 into an oval brilliant of 105.6 carats, which cost it a great deal of weight and gave it its present shape. It is set in the crown of Queen Elizabeth The Queen Mother, also in the Tower. India, Pakistan, Iran and Afghanistan have all asked for it back.
Hope
The most famous blue diamond: 45.52 carats, a deep greyish blue coloured by boron, which also makes it glow red under ultraviolet light for a few seconds. It was cut from the French Blue, bought in India by Jean-Baptiste Tavernier and sold to Louis XIV in 1668, and stolen from the French crown jewels in 1792. The recut stone surfaced in London in the 1830s in the collection of Henry Philip Hope, whose name it kept. Harry Winston gave it to the Smithsonian in Washington in 1958, where it is the most visited object in the museum.
Regent
Found in India in 1698 and bought by Philippe d'Orléans, regent of France, in 1717, which gave it its name. A cushion brilliant of 140.6 carats, considered one of the best-cut of the old Indian stones. It was set in the crowns of Louis XV and Louis XVI, in the hilt of Napoleon's sword, and is now in the Louvre.
Orlov
About 190 carats, a rose-cut stone in the shape of half an egg, cut in India and never recut. Count Grigory Orlov bought it in Amsterdam in the 1770s for Catherine the Great, who had it mounted in the Imperial Sceptre. It is in the Diamond Fund of the Kremlin. It may be the same stone as the Great Mogul described by Tavernier in 1665 and lost since, though that has never been proved.
Dresden Green
The only large natural green diamond, about 41 carats, coloured by natural radiation over millions of years. Bought by Augustus III of Saxony in 1742 and set in a hat ornament that has hardly changed since. It is in the Green Vault in Dresden, which took its name from the vault, not the stone.
Tiffany Yellow
A yellow diamond of 128.54 carats found in the Kimberley mines in 1877 and bought rough by Charles Lewis Tiffany. Cut in Paris with 82 facets, more than a standard brilliant, to hold its colour. It has been worn by four women: Mary Whitehouse in 1957, Audrey Hepburn for the photographs promoting Breakfast at Tiffany's in 1961, Lady Gaga at the 2019 Oscars and Beyoncé in 2021. Otherwise it is on show in the Tiffany store on Fifth Avenue. Read more about New York's diamond district.
Excelsior and Jonker
Two South African giants that were cut into many stones rather than one. The Excelsior, 995 carats, found at Jagersfontein in 1893, was the largest known rough until the Cullinan; Asscher cut it in 1903 into twenty-one stones, the largest under 70 carats, which is why its name is less known than its size deserves. The Jonker, 726 carats, was found in 1934 near Pretoria and cut in New York by Lazare Kaplan into twelve stones, the largest about 125 carats.
The recent ones
The record for a cut diamond belongs to the Golden Jubilee, a brown stone of 545.67 carats from the Premier mine, cut in 1990 and given to the King of Thailand. The Centenary, 273.85 carats and flawless, came from the same mine in 1986. The Lesedi La Rona, 1,109 carats rough, found in Botswana in 2015, was the second-largest rough after the Cullinan and yielded a 302-carat square emerald cut. Botswana has since produced two larger roughs; the record book keeps changing.
What they have in common
Nearly every one of them was recut, often losing half its weight, to suit the taste of a new owner or a new century. The Koh-i-Noor lost 80 carats to become a brilliant. That is a reminder that a diamond is not a fixed object: what you own is the rough's potential, and every cut is a choice. Read more about the four Cs and the old colour names that still turn up on descriptions of these stones.