Over the last 140 years, South Africa’s diamond mines have produced some of the world’s most famous gems in terms of both size and prestige.

Two of South Africa’s most famous large high-quality diamonds, the Excelsior diamond and the Reitz diamond (subsequently renamed the Jubilee), which also rank as two of the ten largest diamonds ever discovered, were sourced from the Jagersfontein diamondiferous kimberlite pipe.

The Jagersfontein mine, one of South Africa’s oldest diamond mines, located in the Free State province, operated between 1871 and 1971 and produced some 9.526-million carats over its life-of-mine.

Although the mine was essentially a cleavage mine – over 50% of the diamonds that were produced from the Jagersfontein mine were in the form of cleavages or fragments – the mine did yield some very large pure blue-white stones, as well as the occasional exquisite stone of deep sapphire blue.

The largest and most famous of the diamonds unearthed from the mine was the 971½ ct Excelsior diamond.

It was discovered on June 30, 1893, by one of the African miners working in the openpit of the mine. For his honesty in handing the diamond over to the mine manager, the finder was rewarded with £500 and given a horse equipped with a saddle and a bridle.

The stone was a beautiful blue-white colour and of the first water, measuring two-and-a-half inches in length, two inches in breadth and one inch in thickness.

Interestingly, until the discovery of the 3 106 ct Cullinan diamond in 1905, the Excelsior was the world’s largest known uncut diamond.

In time, the diamond was shipped to London, where it was handed over to be sold by the famous diamond firm of Wernher Beit & Co. It was valued by a number of different diamond experts at amounts varying between £50 000 and £500 000.

Because of its exceptional size and substantial price tag, no buyer could be found for the rough gem and, as a result, it was decided to have it cut into smaller, more saleable pieces.

Thus, in 1903, the Excelsior was sent to the famous diamond-cutting firm of IJ Ascher, in Amsterdam, where it was cut into 11 smaller gems varying in weight from 9.28 ct to 69.68 ct. Eight of the stones cut from the Excelsior were pear shaped, while the remaining three were round brilliants.

After the cutting and polishing had been completed, the 11 Excelsior diamonds were sold separately. Although people have hazarded guesses as to what became of them, there is uncertainty about the fate of the gems. However, it is known that the Excelsior I, the largest of the cut diamonds, is now owned by Lebanese businessperson Robert Mouawad, who had the diamond reset in an elaborate bracelet.

The other significantly large stone to be unearthed at the Jagersfontein mine was the 634 ct Reitz diamond.

The diamond, which was discovered towards the end of 1895, was named after Free State President Francis William Reitz.

It was acquired by a syndicate of London diamond merchants (comprising Wernher Beit & Co, Barnato Bros and Mosenthal Sons & Co) who, believing that the diamond was too large to sell as one piece, sent it to a diamond-cutting firm in Amsterdam, where it was skillfully cleaved into two pieces.

The first was a piece of about 40 ct which, when cut, yielded a beautiful pear-shaped gem of 13.34 carats, and was sold by Dom Carlos I, of Portugal, as a gift for his wife.

The larger piece of the stone was cut into a faultless brilliant of 239 ct. As this diamond was intended as a gift for Queen Victoria, the diamond was renamed the Jubilee diamond in honour of the celebration of her sixtieth anniversary. However, the diamond was never presented to the Queen but, rather, remained with its owners, who put it on display at the Paris Exhibition of 1900.

Shortly afterwards, the Jubilee diamond was bought by the Indian iron and steel magnate, Sir Dorabji Jamsetji Tata, whose heirs, following his death in 1932, sent it to renowned French jeweller and watchmaker Cartier for sale. In 1937, the Jubilee was sold to Louis-Paul Weiller, the Paris industrialist and patron of the arts, who changed its setting to that of a baguette diamond brooch suggestive in shape of a stylised turtle or a six-pointed star.

Interestingly, the Jubilee’s current owner is also diamond magnate Mouawad and, like the Excelsior I, is understood to be kept at his private museum in Beirut.

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