Because it is the largest gem-quality diamond ever found at over 3,100 carats rough. It helped gain publicity for South African diamond mines and diamonds in general and became part of the crown jewels of the UK. If it ever came up for auction (which it won't because it belongs to the royal family) it would end up selling for several million dollars. It is a very important and priceless gem.
Mother Nature made the Cullinan diamond, which was discovered by a human in 1905.
Thomas Cullinan - diamond magnate - died in 1936.
Thomas Cullinan - diamond magnate - was born in 1862.
Wikipedia estimates the value of the Cullinan 1 diamond at about $400 million. So combined the Cullinan 1 and Cullinan 2 are probably worth over $600 million.
The Cullinan was mined in South Africa, in 1905.
The Cullinan at more than 3,000 carats, remains the largest raw diamond ever found.
From Wikipedia: "The Cullinan diamond is the largest rough gem-quality diamond ever found, at 3,106.75 carats (621.35 g)."
According to Wikipedia: "The Cullinan diamond was found by Frederick Wells, surface manager of the Premier Diamond Mining Company in Cullinan, on January 26, 1905."
The Cullinan diamond is famous for being the largest gem-quality diamond ever discovered, weighing over 3,100 carats in its rough form. It was cut into several smaller diamonds, with the largest pieces adorning the British Crown Jewels. Its exceptional size, quality, and historical significance contribute to its importance in the world of gemstones.
The heaviest diamond in the world is the Cullinan diamond, which weighed 3,106 carats (around 1.37 pounds) in its rough form before being cut into multiple diamonds. The largest cut diamond from the Cullinan diamond, the Cullinan I or Great Star of Africa, weighs 530.2 carats.
The Cullinan diamond was found in Africa in 1905. It was cut into several individual stones, the largest of which were named by appending Roman Numerals after Cullinan. You can read more about these diamonds, below.
First diamond, Cullinan I was called The First star of Africa/ Great star of Africa. You can review the link, below, and learn more about all the finished diamonds cut from the Cullinan.