World's Largest and Most Expensive Diamonds

Discovery: The Cullinan diamond was discovered near Pretoria, South Africa, in 1905. Before it was cut and polished, the original stone weighed 3,106.75 carats and was 4.1 inches long.

Famous for: The rough diamond was cut into 105 diamonds, with nine large and 96 small stones. The largest of the nine diamonds is the Cullinan I, or the Star of Africa, weighing 530.4 carats, making it the world’s largest cut and polished white diamond. The Star of Africa and the rest of the diamonds cut from the original Cullinan belong to the British Crown Jewels.

Value: The Cullinan is estimated to be worth USD 400 million.

Discovery: The origin of the Nameless black diamond or carbonado remains a mystery.

Famous for: This rough diamond was originally 1,000 carats in weight and was cut into a stunning 489.07-carat polished gem. Although scientific studies on the origin of the diamonds point to Brazil or Central Africa as the only possible sources of black diamonds, the origin of the Nameless has not been established, nor is its discoverer or the date of discovery. These circumstances led to the stone being referred to as The Nameless or Anonymous Diamond. The last known record of the Nameless diamond’s activity in the diamond market was its purchase by a still anonymous buyer in 2001.

Value: It was sold in Dole, France, for €1,829,388.

Discovery: The Excelsior was discovered on June 30, 1893, in the Jagersfontein Mine located in South Africa.

Famous for: This gem had a bluish-white tone and weighed 971 carats. Unfortunately, its discovery was not widely publicized in the British newspapers due to the expiration of the mining company's contract and the purchase of the London firms on the same day as the stone’s discovery. The stone was cut into ten gems weighing 13 to 69 carats each. For unknown reasons, a single large piece was never produced from the rough stone. It was cut into small gems of assorted shapes bought by different buyers.

Value: The largest stone cut from the Excelsior diamond, weighing 69.68 carats, was sold in 1996 for $2,646,000. The other smaller stones were used to make fine jewelry, such as bracelets and tiaras.

Discovery: The Star of Sierra Leone was discovered in the Diminico mine in Sierra Leone in February 1972.

Famous for: The Star of Sierra Leone is the world’s third-largest and best gem in quality and the largest diamond discovered in an alluvial mine. It is also known for its perfect chemical purity and the absence of plastic distortions in its crystal. The stone was first cut into an emerald shape, weighing 143.2 carats but had to be re-cut into 17 diamonds that met the perfect cut scale. The largest stone of the Star of Sierra Leone weighs 53.96 carats, cut in a flawless pear shape. Six smaller diamonds were made into a famous brooch called the “Star of Sierra Leone” by the jeweler Harry Winston.

Value: In 1972, the initial cut Star of Sierra Leone was sold to Harry Winston for around USD 2.5 million.

Discovery: The Incomparable was discovered in a pile of rubble in Mbuji Mayi in the Democratic Republic of Congo in the 1980s. The rough stone weighed 890 carats.

Famous for: The extraordinary color of the Incomparable showed varying shades of pale yellow to amber. The biggest cut produced a diamond of 407.48 carats, graded as internally flawless clarity. The Incomparable appeared in an auction in London and then in New York in 1988. It is the biggest diamond to be offered for sale in public but was never sold as the bidding did not reach the seller’s reserved price of USD 20 million.

Value: Estimated at USD 20 million.