The Star of Africa

Of all the famous diamonds in the world, the most impressive is surely the Star of Africa, also known as Cullinan I, after Sir Thomas Cullinan, the owner of the mine in which it was found. The person who found the diamond itself was a man called Frederick Wells.

One evening, while on an inspection of the mine, Wells noticed something catching the rays of the setting sun. He looked closer, and saw an object embedded in the wall of the mine, some 18 feet below ground level. He pulled out what seemed to be a large diamond crystal. (As superintendent of the mine, Wells would have been very familiar with the appearance of a rough diamond).

At first, he thought that it might have just been a piece of glass, such was the size of the stone. It weighed 3106 carats, slightly over half a kilogram. The stone appeared to have been fragmented while in the ground, giving rise to the intriguing possibility that there is another fragment or fragments somewhere under the ground. To this day none t has never been found. Given the shape and direction of the cleavage of the diamond, it would be likely that the undiscovered pieces are even larger!! The size of the rough diamond can be seen in the picture below, and a life-sized replica that we have on display in our shop on Clarendon Street. The discovery made headlines around the world, and caused the share price of the mining company to jump 80-fold. The Premier Mine, where it was found, is still in operation today, yielding more that one million carats per year. Currently the mine is operating over 700 metres below the surface, with plans to go down to 1100 metres.


cullinan replica

The diamond was initially sold to the government of Transvaal for £150,000, which was a tidy profit for the mining company, who has paid only £52,000 for the land. The stone was subsequently presented to the King of England, Edward VII, to mark his 66th birthday and as a “token of the loyalty and attachment of the people to Transvaal to {the king}”. It was insured for 1.25 million pounds.

The job of cutting the diamond was given to Asscher’s, of Amsterdam, who are also famous for their eponymous cut.

Preparation and analysis took months, and in 1908 the cutting process began. The stone was cut initially into 11 pieces. In total, the diamond produced nine major gems, ninety six smaller diamonds, and 9.50 carats of unpolished diamonds. The nine major diamonds were named Cullinan One to Nine, generally given the Roman numerals. Cullinan I weighed 530 carats, and Cullinan II weighed 317 carats. Work began in February 1908, and was finished in September of the same year, thanks to three polishers working 14 hours a day.


Cullinan I was cut as a pear shape. It weighs 530 carats, and was placed in the Royal Sceptre. In the picture below, we can see King Edward holding the Sceptre, before the diamond was added.

Cullinan II was cut as a cushion cut diamond. It was placed in the Imperial State Crown. It weighs 317 carats. It is the large diamond in the main band.

Cullinan III is a 94 carat pear shape diamond; it can be worn as a brooch, along with Cullinan IV, a 63 carat cushion cut diamond. This brooch is known as “Granny’s Chips” by the Royals, as it was originally the property of Queen Mary, (the grandmother of Queen Elizabeth II) a gift to her from the people of South Africa. It is currently the property of Queen Elizabeth II, and is thought to be worth over fifty million pounds.

Cullinan V is an 18 carat heart shape diamond.

Cullinan VI is an eleven carat marquise shape diamond; this was purchased by King Edward for his consort, and set into a diamond and emerald necklace.

Cullinan VII is a marquise shape diamond, and is mounted is a brooch with Cullinan VIII.

Cullinan IX is a pear shape diamond, set into a ring.

The total weight of the polished diamonds was 1,063 carats. There was a 65% loss from the rough diamond. The Star of Africa can be seen today in the Tower of London. Modern gradings reveal that the Cullinan I and II stones are D colour, potentially flawless clarity, and of chemical Type IIa, a combination of factors that is virtually unheard of in diamonds of this size.

Cullinan major diamonds