Identifying the most valuable diamonds in the world is much more challenging than you might imagine. Many of the world's largest, rarest and most famous diamonds have not been sold for a very long time, and it is hard to know what a buyer might be willing to pay for them. Moreover, the value of these very special stones isn't just determined by the 4Cs of carat weight, colour, clarity and cut but also by factors such as their historical and symbolic value. Nonetheless, we've applied our diamond expertise and some common sense to pull together the definitive list of the 20 most valuable diamonds in the world. Drumroll, please...
20. The De Beers Blue: £50 million
Discovered as a rough stone in South Africa's historic Cullinan mine in April 2021 and weighing 15.10 carats, the De Beers Blue is the largest internally flawless step-cut vivid blue diamond ever graded by the Gemological Institute of America (GIA). Sold at Sotheby's in Hong Kong in 2022 for US$57.5m, it is the largest and most valuable blue diamond ever sold at auction.
Blue diamonds are exceptionally rare, with their beautiful colour being caused by the presence of trace amounts of the element boron within the diamond crystal lattice. Only five fine blue diamonds over 10 carats have ever come to auction, and The De Beers Blue is the only one to have exceeded 15 carats.
19. The Blue Moon of Josephine: £75 million
The Blue Moon of Josephine is a 12.03ct cushion cut diamond, graded as Fancy Vivid Blue and Internally Flawless by the GIA.
The diamond was discovered in January 2014 at the Cullinan mine in South Africa. The rough stone initially weighed 29.6 carats before being meticulously cut and polished.
The Blue Moon of Josephine was sold at a Sotheby's auction in Geneva in November 2015. The final price was $48.4 million, which at just over $4 million per carat made it the world's most expensive diamond per carat at that time. The buyer, Hong Kong billionaire Joseph Lau, named the diamond after his daughter, Josephine.
Fancy Vivid Blue diamonds are exceedingly rare, and the Blue Moon of Josephine's combination of colour intensity, clarity, and carat weight make it one of the most remarkable blue diamonds ever discovered.
18. The Oppenheimer Blue: £75 million
The Oppenheimer Blue is a rectangular-shaped diamond with a Fancy Vivid Blue colour and a VVS1 clarity (Very Very Slightly Included). It weighs 14.62 carats, making it one of the largest blue diamonds of its kind.
Named after its previous owner, Sir Philip Oppenheimer, it has a fascinating history and exceptional characteristics. Sir Philip Oppenheimer was the head of the Central Selling Organisation for De Beers and was a key figure in the global diamond industry for many years. The Oppenheimer Blue was part of his personal collection.
In May 2016, the Oppenheimer Blue was put up for auction at Christie's Geneva. Leading up to the auction, it garnered significant attention from collectors and media due to its size, colour, and association with Sir Philip Oppenheimer.
After an intense bidding war, the Oppenheimer Blue was sold for $57.5 million, setting a new record at that time for the most expensive diamond ever sold at auction.
Its exact whereabouts since the sale are not publicly known, adding a touch of mystery to this extraordinary gemstone.
17. The CTF Pink Star: £75 million
The CTF Pink Star, formerly known simply as the Pink Star, is a stunning 59.60ct oval cut diamond, graded Fancy Vivid Pink and Internally Flawless diamond. Its colour is incredibly rare, with no trace of an overtone or secondary colour, and its clarity is such that no internal imperfections are visible under standard grading conditions. Pink diamonds owe their colour to a distortion in their crystal lattice, but the shade of pink varies widely between individual gems. The CTF Pink Star's particularly vivid pink contributes to its exceptional value.
The rough diamond was discovered in South Africa in 1999 by De Beers and weighed 132.5 carats. The stone was then meticulously cut and polished over a period of nearly two years by Steinmetz Diamonds. The cutting process was extraordinarily complex, requiring precise planning and execution to retain the stone's unique colour while maximizing its brilliance.
In 2013, it was sold at auction by Sotheby's Geneva for $83.2 million, but the buyer defaulted on the payment, so the diamond was returned to Sotheby's inventory.
Then in April 2017, it was again auctioned by Sotheby's in Hong Kong, where it was sold for $71.2 million to Chow Tai Fook Enterprises, a Hong Kong-based conglomerate. The diamond was subsequently renamed the CTF Pink Star in honour of the company's late founder, Dr Cheng Yu-Tung.
The CTF Pink Star holds the title for the largest Internally Flawless, Fancy Vivid Pink diamond ever graded by the GIA, as well as setting a new for the highest price ever paid for a diamond or any gemstone at auction.
16. The Paragon: £75 million
The Paragon is a D colour, Flawless clarity diamond, weighing a remarkable 137.82 carats. It's a seven-sided kite-shaped gem, making it an unusual and distinctive shape among famous diamonds.
The origins of the diamond are shrouded in mystery. The mine where it was discovered has never been publicly disclosed, nor has the date of its discovery or the weight of the rough diamond.
However, it is said that it was cut and polished over two years before being unveiled by Graff Diamonds in 1999 as a unique seven-sided kite shape cut. This highly unusual cut is thought to have been chosen to retain a significant portion of the rough weight and showcase the diamond's clarity and brilliance.
Graff Diamonds set the Paragon into a necklace featuring a collection of other rare and flawless white diamonds. The necklace itself is an exquisite piece of jewellery, and the Paragon, as its centrepiece, adds a striking focal point.
The Paragon's characteristics place it among the largest flawless diamonds in the world. Its D colour rating signifies that it is completely colourless, the highest grade for a white diamond, and its Flawless clarity means no internal or external imperfections are visible under standard grading conditions. The combination of these factors and its unique cut makes it an extraordinary gemstone.
15. The Graff Pink: £100 million
The Graff Pink is a rare Fancy Intense Pink diamond weighing 24.78 carats. Its colour is evenly distributed, and it has been graded as being Internally Flawless.
Details about the origins of the diamond are scarce. It was previously owned by the famous American jeweller Harry Winston, who held the gem in his private collection for decades. In November 2010, the stone was auctioned by Sotheby's in Geneva and was purchased by Laurence Graff, founder of Graff Diamonds, for $46 million, setting a record at that time for a single gemstone sold at auction.
After purchasing the diamond, Graff had it re-cut, slightly altering its shape to remove its clarity.
The Graff Pink has since been set into a ring, surrounded by two shield-shaped diamonds on either side. The setting was designed to showcase the extraordinary colour and clarity of the diamond.
Fancy Intense Pink diamonds are extremely rare, especially in larger sizes, and the Graff Pink's combination of colour, clarity, and size places it in an elite category.
The Wittelsbach-Graff is a 31.06-carat deep-blue diamond that was discovered in the mid-1600s in the Kollur mines in the Guntur district of Andhra Pradesh, India. This mine is known for producing other famous diamonds, such as the Hope and Regent diamonds.
It was purchased in 1664 by King Philip IV of Spain for his daughter, the Infanta Margarita Teresa, upon her engagement to Emperor Leopold I of Austria. The diamond remained in Austria until 1722 when it was passed on to the Wittelsbachs, a Bavarian royal house. The diamond disappeared in the 20th century, likely due to the tumult of World War I and the Bavarian Revolution, before it resurfaced in 1962 at a Christie's auction and was identified as the missing Wittelsbach Diamond in 1964.
In 2008, Graff Diamonds purchased it at a Christie's auction for £16.4 million. Graff then controversially had the diamond recut to remove flaws, reducing its size but enhancing its colour and clarity. The GIA graded the recut diamond as Fancy Deep Blue. The recutting of the diamond has been a point of contention among historians and gemologists, as the process altered a historical gem and made it difficult to compare directly with the French Blue Diamond (the Hope Diamond). However, others argue that the enhancements improved the diamond's value and beauty.
13. The Regent: £150 million
The Regent Diamond is one of the most famous diamonds in the world, known for its exceptional clarity, perfect cut, and intriguing history.
Allegedly discovered by a slave in 1698 in the Kollur mines in India, the rough diamond was initially 410 carats. Legend has it that the slave hid it inside a large wound in his leg before giving the diamond to a sea captain in return for passage. Instead, the captain is said to have killed him before the diamond changed hands several times, eventually before being sold to Thomas Pitt, the English governor of Madras, in 1701.
Pitt had the diamond cut in London. The process took two years and reduced the diamond to 140.50 carats. In 1717, Pitt sold the diamond to the Duke of Orleans, Regent of France, for the equivalent of £135,000. The diamond was then named "The Regent."
The Regent Diamond was set into the crown of Louis XV for his coronation in 1722. It was also used in the royal crowns of Louis XVI and Napoleon Bonaparte. Marie Antoinette and Marie Louise, Napoleon's second wife, both wore the Regent as part of their jewellery.
After surviving the French Revolution, the Regent Diamond is now on display at the Louvre Museum in Paris, France. It is part of the French Crown Jewels.
12. The Millennium Star: £150 million
The Millennium Star was discovered in the Democratic Republic of Congo in 1990, and the rough stone weighed 777 carats, making it the sixth-largest diamond of gem quality ever discovered.
The De Beers Group acquired the diamond and spent several years studying and cutting the stone. The resulting pear cut diamond weighs 203.04 carats, with the highest colour grade (D colour, completely colourless) and the highest clarity grade (Flawless).
The diamond was publicly unveiled as the centrepiece of De Beers' "Millennium Jewels" collection in 1999 to celebrate the new millennium. The collection, displayed in London's Millennium Dome, was the target of a failed robbery attempt in 2000.
11. The Centenary: £175 million
The Centenary Diamond was discovered in the Cullinan Mine in South Africa on July 17, 1986. The rough stone weighed in at 599 carats, making it the largest diamond ever to be recovered from the Premier Mine at that time.
The task of cutting and polishing the Centenary Diamond was given to the master cutter Gabi Tolkowsky by De Beers. The process took nearly three years to complete. The final result was a modified heart-shaped brilliant cut diamond weighing 273.85 carats. The Centenary Diamond has 247 facets: 164 on the pavilion and crown and 83 on the girdle. It is the largest diamond in the world that has been classified by the GIA as both D colour (the highest colour grade possible, completely colourless) and Flawless clarity.
The diamond was named the "Centenary Diamond" because it was unveiled in final form by De Beers in May 1988 as part of their centennial celebrations. At its unveiling, it was insured for $100 million.
10. The Jacob Diamond: £200 million
The Jacob Diamond, also known as the Imperial or Victoria Diamond, was discovered in the Kollur mines in India, in the 19th century. It's a colourless, cushion cut diamond weighing approximately 184.75 carats, making it one of the largest diamonds in the world.
The diamond is named after Alexander Malcolm Jacob, who acquired it from the mines. He later sold it to the sixth Nizam (ruler) of Hyderabad, Mahbub Ali Pasha, around 1891, under controversial circumstances resulting in a legal dispute.
The seventh Nizam, Mir Osman Ali Khan, used the diamond as a paperweight for many years, and it was kept in the toe of his father's shoe in the royal treasury.
After India's independence and the subsequent annexation of Hyderabad, the diamond, along with other jewels from the Nizam's collection, became the property of the Indian government. The Jacob Diamond is now part of the Nizam's jewellery collection, which is occasionally exhibited in the National Museum and the Salar Jung Museum in Delhi.
9. The Graff Lesedi La Rona: £200 million
The Lesedi La Rona, meaning "Our Light" in the Tswana language, was discovered in the Karowe mine in Botswana on November 16, 2015. It was the largest diamond discovered in over 100 years and the second-largest gem-quality diamond ever found, weighing a staggering 1,109 carats in its rough state.
Graff purchased the diamond for $53 million in 2017. The process of analyzing, cutting, and polishing the diamond took more than 18 months. Using advanced imaging technology, Graff and his team painstakingly transformed the rough stone into a collection of stunning, D-colour, high-clarity diamonds. The largest diamond cut from the Lesedi La Rona weighs an impressive 302.37 carats and is the world's largest Asscher cut diamond, also known as a square emerald cut diamond.
8. The Dresden Green: £250 million
The green colour is usually a result of radiation exposure, and the colour is usually only skin-deep. However, the Dresden Green's colouration is evenly spread throughout the diamond, making it unique. In 2000, the gemstone was studied by the GIA and found to be a type IIa diamond, the purest type.
The diamond is thought to have been found in the Golconda region of India but gets its name from the capital city of Saxony in Germany. It was purchased by Augustus III of Poland from a Dutch merchant in 1742. The diamond is a part of the Saxon State and University Library Dresden (SLUB) and is usually displayed in Dresden's Green Vault at Dresden Castle. The castle was targeted in a significant jewellery heist in 2019, but The Dresden Green Diamond was not stolen as it was on loan to the Metropolitan Museum of Art in New York at the time.
7. The Hope: £250 million
The Hope Diamond weighs approximately 45.52 carats and is cut into a cushion antique brilliant with a faceted girdle and additional facets on the pavilion. The diamond's colour is described as "Fancy dark greyish-blue". It is classified as a Type IIb diamond, a rare type that accounts for less than 0.2% of all diamonds and is known for its phosphorescence, glowing red under ultraviolet light (a characteristic of Type IIb diamonds).
The origins of the Hope Diamond are traced back to India, where it's believed to have been part of the famous statue of the Hindu god Sita. The first verified owner was Jean-Baptiste Tavernier, a French gem merchant who bought the diamond (then a larger 112 3/16-carat stone) in the mid-17th century. Tavernier sold the diamond to King Louis XIV of France, who had it recut into a 67-carat stone known as the "French Blue."
The crown jewels, including the French Blue, were stolen during the French Revolution. The diamond disappeared and was likely recut into smaller stones, one of which is believed to be the Hope Diamond. The diamond resurfaced in London in 1812, just about 20 years after the statute of limitations for the French theft had expired. Henry Philip Hope bought the diamond, which became known as the "Hope Diamond."
Many owners of the Hope Diamond have experienced great misfortune, leading to the legend of a curse associated with the diamond. Owners faced financial ruin, failed marriages, death, and other miseries. However, some believe the "curse" was a story made up by Pierre Cartier to entice Evalyn Walsh McLean to buy the diamond in 1911.
In 1949, Harry Winston, the New York gem merchant, purchased the diamond from Evalyn Walsh McLean's estate. In 1958, Winston donated the Hope Diamond to the Smithsonian's National Museum of Natural History in Washington, D.C., where it remains to this day.
6. The Orlov: Priceless
The Orlov Diamond, also known as the Orloff Diamond, is a large diamond of Indian origin, currently displayed in the Diamond Fund collection of the Kremlin Armoury in Moscow.
It weighs approximately 189.62 carats, is bluish-white and has exceptional clarity. The diamond is rose cut, an older style of cutting that typically produces gems with a somewhat round, dome-like appearance. However, the Orlov has quite an unusual shape, described as being like half a chicken's egg, which is a shape associated with Indian diamonds in the Mughal period.
The exact origins of the Orlov Diamond are not entirely known, but it's believed to have been discovered in the Kollur mines in India. The diamond was reportedly set as one of the eyes in a statue of a Hindu god in a temple in Sri Rangam before being stolen in the 18th century by a French deserter. According to legend, the soldier disguised himself as a Hindu holy man to gain access to the temple and spent years gaining the priests' trust before he stole the diamond.
The diamond eventually made its way to Amsterdam, where it was bought by Count Grigory Grigorievich Orlov. The Count gave the diamond to Empress Catherine the Great of Russia. He had been romantically involved with Catherine in the past, and it's often suggested that he gave her the diamond in an attempt to win her back after she had left him for another man. Unfortunately, Catherine did not return to him, but she did keep the diamond and had it set into her Imperial Sceptre.
5. The Cullinan II: Priceless
The Cullinan II Diamond is the second-largest gem that was cut from the Cullinan Diamond, the largest gem-quality diamond ever found. The Cullinan Diamond was an extremely rare Type IIa diamond that was discovered in 1905 in the Cullinan Mine in South Africa, and it originally weighed a staggering 3,106.75 carats.
The mine's owner, Sir Thomas Cullinan, sold the rough diamond to the Transvaal Colony government, which presented it to King Edward VII of Britain on his 66th birthday, and the diamond was subsequently cut and polished by the renowned Asscher Brothers of Amsterdam, who studied the diamond for several months before making the initial cut.
The first attempt to cleave the diamond broke the blade, leaving the diamond unscathed. On the second attempt, the diamond was successfully cleaved into two pieces, and further cutting and polishing led to nine major stones and numerous smaller fragments. The Cullinan II is the second largest of these stones.
The Cullinan II, also known as the Second Star of Africa, is the world's fourth-largest diamond, weighing about 317.4 carats. It is a cushion cut brilliant with 66 facets and has the same unblemished clarity as all diamonds in the Cullinan family, and is of a similar top-quality colour.
After the cutting was completed, the Cullinan II was set into the British Imperial State Crown. The diamond is part of the British Crown Jewels and is on display in the Tower of London.
4. The Noor-ol-Ain: Priceless
The Noor-ol-Ain diamond is one of the most famous diamonds in Iranian history. The name of the diamond translates from Farsi to "The Light of the Eye". On display at the Central Bank of Iran in Tehran, the Noor-ol-Ain diamond is a centrepiece of the Iranian Crown Jewels, one of the largest jewellery collections in the world.
Weighing approximately 60 carats, it is one of the largest pink diamonds in the world. A brilliant cut oval diamond, the Noor-ol-Ain diamond has an intensity of colour that makes this gem particularly unique.
The Noor-ol-Ain is believed to have been discovered in the Kollur mines in India, just like many other historic diamonds. These mines were famous for producing large, high-quality diamonds in the 16th and 17th centuries.
The diamond's early history is not well documented, but it came into prominent recognition in the 19th century when it was used along with several other large diamonds to adorn the elaborate Peacock Throne of the Persian (Iranian) Shahs.
The Noor-ol-Ain was mounted in a tiara for the wedding of Empress Farah Pahlavi to Shah Mohammad Reza Pahlavi in 1958. The tiara was designed by Harry Winston and included 324 pink, yellow, and white diamonds, with the Noor-ol-Ain as the centrepiece.
3. The Koh-i-Noor: Priceless
The Koh-i-Noor Diamond is one of the world's most famous and historically significant diamonds. Its name translates from Farsi to "Mountain of Light," reflecting its extraordinary beauty and brilliance.
The Koh-i-Noor is a colourless diamond and weighs 105.6 carats. It's known for its exceptional size and oval cut and is classified as a Type IIa diamond, which makes up less than 2% of all gem diamonds and is almost or entirely devoid of impurities.
The Koh-i-Noor's history spans over 700 years, making it one of the oldest known diamonds. Its early history is murky, but it is thought to have originated from the Golconda mines in India. Various Indian, Persian, and Afghan rulers have owned the diamond.
During the British conquest of the Punjab in 1849, the British East India Company took possession of the diamond before presenting it to Queen Victoria in 1850. Initially, the diamond was not well-received in the British court, so it was recut from 186 carats to its present 105.6-carat form to enhance its brilliance.
The ownership and legal status of the Koh-i-Noor have been contentious. Various governments and individuals have demanded its return to India, Afghanistan, Pakistan, and Iran. The British government has maintained that the gem was obtained legally under the Treaty of Lahore and has rejected calls for its return.
The Koh-i-Noor is now set in the front of the Queen Mother's Crown, part of the British Crown Jewels, and has been worn by Queen Alexandra, Queen Mary, and Queen Elizabeth The Queen Mother.
The Koh-i-Noor is associated with a legend that says the diamond carries a curse and brings misfortune or death to any male who wears it. However, it's supposedly benign to female owners. This legend might explain why the Koh-i-Noor has only been worn by queens and queen consorts since coming into British possession.
The Koh-i-Noor holds a unique place in history and remains on display in the Tower of London, where it continues to attract attention and controversy.
2. The Daria-i-Noor: Priceless
The Daria-i-Noor, which translates to "Sea of Light" in Farsi, is one of the largest pink diamonds in the world. It is estimated to weigh around 182 carats and is pale pink. It is also an exceptionally rare Type IIa diamond, which means it has few or no nitrogen impurities.
It has been cut and polished into a form known as a "tabular cut," which is a more traditional and ancient way of shaping diamonds. This type of cut produces a flat, table-like surface on the top with more facets on the bottom to reflect light. The tabular cut might not deliver the same level of brilliance and fire seen in modern brilliant cuts, but it provides a unique appearance that can emphasize the stone's colour and clarity.
Like many famous diamonds, the Daria-i-Noor's origins can be traced back to the Kollur mines in India. The diamond's early history is somewhat uncertain, but it became part of the spoils of various Indian, Persian, and Afghan rulers.
Nader Shah of Persia brought the Daria-i-Noor to Persia (now Iran) in the 18th century after a successful invasion of India. After Nader Shah's death, the diamond passed through various hands before becoming part of the Persian Crown Jewels, now the Iranian Crown Jewels. It's one of the most celebrated diamonds in the collection and has been set in a frame studded with 457 diamonds and four rubies. The jewel is kept in the Central Bank of Iran in Tehran.
It's believed that the Daria-i-Noor might have been part of a larger pink diamond that was cut into two pieces. The other piece is thought to be the Noor-ol-Ain diamond.
1. The Cullinan I: Priceless
The Cullinan I diamond, also known as the Great Star of Africa, is the largest cut and polished white diamond in the world and is one of the most famous gemstones ever discovered. Weighing an astonishing 530.2 carats, it is a Type IIa pear cut diamond with 74 facets.
Like the Cullinan II (see above), its smaller sibling, The Cullinan I was cut from the Cullinan Diamond, the largest gem-quality diamond ever found.
The Cullinan I is set in the head of the Sovereign's Sceptre with Cross, part of the British Crown Jewels. It has been designed so it can be removed from the sceptre and worn as a pin or pendant.
The other significant stones cut from the original Cullinan Diamond include the Cullinan II, also known as the Second Star of Africa, which is set in the Imperial State Crown, and various other stones that are part of the British royal collection or held by other members of the British royal family.