Beyond Koh-i-Noor: 5 of the World’s Most Stunning and Valuable Diamonds
The Koh-i-Noor may be one of the world’s most famous diamonds, but it is far from the only extraordinary gem to capture global attention. Some diamonds are celebrated for their enormous size, others for exceptionally rare colours, while a few have achieved extraordinary prices at auction.
Unlike the Koh-i-Noor, whose historical significance makes assigning a conventional market price difficult, several famous diamonds have publicly documented valuations or auction records. Here are five remarkable stones that stand out for their beauty, rarity and fascinating histories.
1. Cullinan I — The Star of Africa
The Cullinan I, also known as the Great Star of Africa, is one of the most famous diamonds ever cut.
It was fashioned from the Cullinan rough diamond, discovered in South Africa in 1905 and widely regarded as the largest gem-quality rough diamond ever found. The finished Cullinan I weighs 530.2 carats and is a pear-shaped brilliant-cut stone.
Today, it is mounted in the Sovereign’s Royal Sceptre and forms part of the British Crown Jewels.
Its immense size and royal history make it virtually impossible to value like an ordinary gemstone.
2. Hope Diamond
Few diamonds are as instantly recognizable as the Hope Diamond.
The spectacular 45.52-carat deep-blue diamond is renowned for its intense colour and long history. It is currently displayed at the Smithsonian’s National Museum of Natural History in Washington, D.C.
Its blue colour comes from trace amounts of boron within the diamond’s crystal structure. The combination of its size, colour, provenance and legendary history makes the Hope Diamond one of the world’s most famous gemstones.
Because it is a museum treasure and not regularly traded, its frequently quoted multi-million-dollar valuations are estimates rather than auction prices.
3. CTF Pink Star
If actual auction price is the benchmark, the CTF Pink Star stands in a league of its own.
The 59.60-carat Fancy Vivid Pink, Internally Flawless diamond sold at Sotheby’s Hong Kong in 2017 for approximately $71.2 million, making it the most expensive gemstone or jewel ever sold at auction.
The stone originally came from a 132.5-carat rough diamond mined by De Beers in Africa in 1999. It took around two years of cutting and polishing to transform the rough stone into the spectacular oval diamond seen today.
Its combination of size, vivid pink colour and exceptional clarity makes it one of the rarest diamonds in the world.
4. Oppenheimer Blue
Blue diamonds are among the rarest coloured diamonds, and the Oppenheimer Blue is one of the most celebrated examples.
The 14.62-carat Fancy Vivid Blue diamond was named after Sir Philip Oppenheimer, a prominent figure in the De Beers diamond industry. In 2016, it sold at Christie’s Geneva for approximately $57.5 million.
Its rectangular step-cut design gives the stone a distinctive, elegant appearance, while its intense blue colour makes it exceptionally valuable.
The Oppenheimer Blue’s auction record remained a benchmark for blue diamonds until the De Beers Blue came remarkably close.
5. De Beers Blue
The De Beers Blue is a relatively recent addition to the elite group of record-breaking diamonds.
Weighing 15.10 carats, it is a Fancy Vivid Blue diamond with a step cut. It was sold at Sotheby’s Hong Kong in 2022 for approximately $57.5 million, almost exactly matching the price achieved by the Oppenheimer Blue.
What makes its story even more remarkable is its origin: the rough stone was discovered in 2021 at South Africa’s Cullinan Mine, one of the world’s few important sources of exceptional blue diamonds.
Why Are These Diamonds So Valuable?
A diamond’s value isn’t determined by carat weight alone. The traditional **4Cs—colour, clarity, cut and carat—**all play a role, but exceptional coloured diamonds can command extraordinary premiums.
Pink and blue diamonds are particularly coveted because truly intense colours are exceptionally rare. The closure of Australia’s Argyle mine in 2020, historically a major source of pink diamonds, has further highlighted the scarcity of top-quality pink stones.
That’s why a relatively small coloured diamond can sometimes sell for far more than a much larger colourless stone.
From the enormous Cullinan I to the vivid CTF Pink Star, these diamonds demonstrate that the world’s most valuable gems aren’t defined simply by size. Rarity, colour, history and provenance can transform a piece of crystallized carbon into a priceless piece of human history.