1. Cullinan Diamond
The Cullinan Diamond is the largest diamond ever found in the world. It was found in a mine in South Africa by Sir Thomas Cullinan in 1905. Before the Cullinan Diamond was cut into polished diamonds, it weighed a whopping 3,106.75 carats (621.35 g)! The rough diamond was split into two stones which were further cut down into nine major stones, 96 brilliants, and 9.5 carats (1.9 g) of unpolished pieces.The two largest stones, the Cullinan I (Great Star of Africa) and Cullinan II, were given to King Edward II and are now part of the Crown Jewels of the United Kingdom.
2. Lesedi La Rona
The Lesedi La Rona, which was found in 2015 is 1,109 carats (221.8 g) and comes from the Lucara Karowe Mine in Botswana. Lucara Diamond, the owners of the mine, only recently sold the Lesedi La Rona in 2017 for $53 million.
The Lesedi La Rona is now owned by British jeweler Graff Diamonds. In early November 2018, Graff revealed that they had cut the Lesedi La Rona into 60 diamonds that are now being incorporated into pieces of jewelry. Graff Diamonds is still working on the Lesedi La Rona and more finished pieces will be released in the future.
3. Excelsior Diamond
The Excelsior Diamond was discovered on June 30, 1983 at the Jagersfontein Mine in South Africa. For the next few decades, the Excelsior Diamond was the largest diamond ever found until the discovery of the Cullinan Diamond in 1905. It weighed in at 995.2 carats (194.35 g), which was unheard of at the time.
Unlike the other large diamonds on the this list, the history of the Excelsior Diamond is not well documented and is considered a mystery. For many years, the Excelsior Diamond remained safely in a vault when the owner decided to cut it into many smaller stones. None of the cut stones from the Excelsior Diamond are notable in size or name.
4. Star of Sierra Leone
The Star of Sierra Leone is the largest diamond to ever come out of the Republic of Sierra Leone, which has produced a few other notable diamonds. Overall, the Star of Sierra Leone is the fourth largest gemstone quality diamond, but is considered the largest alluvial diamond ever found.
The Star of Sierra Leone diamond was 969 carats (193.8 g). A few months after being discovered in early 1972, famous New York City jeweler Harry Winston purchased the Star of Sierra Leone for $2.5 million. The Star of Sierra Leone was cut into several smaller diamonds and six of the diamonds were put into a single brooch, which was sold for an undisclosed amount to a private buyer in 1975.
5. Lesotho Legend
The Lesotho Legend was very recently discovered in early 2018 by Gem Diamonds Ltd. at their mine in Letseng, Lesotho. Weighing in at 910 carats (182 g), the Lesotho Legend is the fifth largest diamond ever found.
Also the quality of the Lesotho Legend is exceptional, it is classified as a D color Type IIa diamond, which means it is the most chemically pure type of diamond. This makes the Lesotho Diamond one of the most valuable diamonds in the world and it was sold for $40 million in March.
According to largest.org