Of all the valuable gemstones money can buy, diamonds are the most prized. Over the years, some shockingly large diamonds have been found, with the most valuable of them kept in museums and royal collections.
The five on this list are worth the most— and all of them are expensive enough to cover the cost of at least a few mansions, plus a Maserati or 10 thrown in.
Why Are Diamonds the Most Valuable Gemstone?
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As you've probably noticed, even ordinary diamonds of decent quality are worth a hefty sum, and there's a good reason for that. While diamonds aren't actually rare, the majority of them found are "industrial grade." Industrial-grade diamonds are dull in color and are far too plain to be used in jewelry or kept in a collection. Instead, they're ground up into dust for use in manufacturing.
For a diamond to be valuable, the weight, clarity, color and cut all come into play. The most expensive diamonds in the world are all examples of exceptional diamonds, boasting extremely rare colors, unusual sizes and impeccable clarity. Just wait until you see No. 1 on this list. It's quite literally a crown jewel.
5. The Pink Star Diamond
Estimated worth: $71.2 million
Coming in at No. 5 is the Pink Star Diamond. It was mined by De Beers in 1999 in Africa, although no one is sure of the exact location it was discovered. In its raw state, it weighed 132.5 carats. After two years of meticulous cutting and polishing by the Steinmetz Group, it was presented to the world as a pristine 59.6 carat, internally flawless gemstone.
It's the world's largest pink diamond, and it was first displayed to the public in 2003 in Monaco. It wasn't sold until 2017 at a Sotheby's auction in Hong Kong to a jewelry company there called Chow Tai Fook. Commanding a price of $71.2 million, it remains the most expensive diamond ever sold at an auction. The buyer named it the CTF Pink Star to honor the legacy of his family's business.
4. The De Beers Centenary Diamond
De Beers Group / Internet Stones
Estimated worth: $90 million
In 1986 in the heart of the Premier Mine in South Africa, a massive 599-carat diamond was unearthed. It was unveiled two years later at the 100th anniversary of De Beers, fittingly dubbed the Centenary Diamond. It was carefully cut down into a heart-shaped gem weighing 273.85 carats. The glittering stone has 247 facets and was given a D rating, which is the highest possible rating for colorless diamonds.
At the time, it was the largest known clear, modern-cut diamond, with flawless clarity inside and out. While it has never officially been valued, it was insured for $100 million before it was put on display in the 1990s. Interestingly, no one knows who owns the diamond or where it's located today.
3. The Hope Diamond
Estimated worth: $200-350 million
Pictured on display at the National Museum of Natural History in 1974, the Hope Diamond is one of the largest blue diamonds ever discovered. It was originally purchased by a French traveler named Jean Baptiste Tavernier, weighing 112 carats. It likely originated from the Golconda mine and was described to have a deep violet color.
Tavernier sold it to King Louis XIV, who had it set into his crown. It was stolen in 1792 but later resurfaced with part of the tear shape missing, likely cut away by the thief in hopes of disguising it. Now weighing 45 carats, it was passed between various royal hands before ending up in the Smithsonian Institution in 1958. Since then, the vibrant gem has only been displayed outside the museum four times.
2. The Cullinan I Diamond
Estimated worth: $400 million
In 1905, the largest rough diamond was discovered in South Africa. Named the Cullinan diamond after the mine's chairman, its starting weight was 3,106 carats. It was broken down into 105 individual gemstones of varying cuts and weights, including the nine major stones pictured here. Just those nine total about 1,055 carats.
The largest piece, Cullinan I, weighs 530.2 carats. It's the largest clear-cut diamond known to man, and it's currently mounted on the scepter of Queen Elizabeth II. It's known as the Star of Africa, with the slightly smaller Cullinan II known as the Lesser Star of Africa. All of the other major Cullinan diamonds currently belong to the queen as well.
1. The Koh-i-Noor Diamond
Cyril Davenport / Wikimedia Commons
Estimated worth: $170-480 million
Pictured here in the cross of Queen Mary's Crown, the Koh-i-Noor is a valuable diamond in a league all its own. Meaning "Mountain of Light," the Koh-i-Noor started out at 793 carats. It was cut and polished into a 105.6-carat gemstone in the 11th or 12th century. It passed through many royal hands in India until it fell into the hands of the British during the 1800s, where it has remained ever since.
It was set in the crown of Queen Elizabeth, the Queen Mother — aka Queen Elizabeth II's mother. It hasn't been seen by anyone outside the royal family since 2002 when the crown rested atop the Queen Mother's coffin during her funeral ceremony.
Fun fact: The Koh-i-Noor is believed by some to be cursed. Many of the men who owned it suddenly fell from power or passed away, so it's only been carried by women since the mid-1800s. The entire collection of gems owned by the British royal family, known as the Crown Jewels, is estimated to be worth more than $10 billion.