Jewellery made from the world's largest diamond is to go on display

Exhibition curator Caroline de Guitaut holds the Cullinan III and IV Brooch. Photographer: Ian Jones
Release date: 
Wednesday, 16 May 2012

Jewellery made from the largest diamond ever found will go on display at Buckingham Palace this summer in the special exhibition Diamonds: A Jubilee Celebration, part of the Summer Opening of Buckingham Palace (30 June – 8 July & 31 July – 7 October)

The exhibition, which celebrates Her Majesty The Queen’s 60 years on the throne, reunites for the first time seven of the nine principal stones cut from the Cullinan Diamond. These seven stones are set in brooches, a ring and a necklace, most of which have been worn by The Queen throughout her reign.  The remaining two stones form part of the Crown Jewels.

The exhibition includes a number of The Queen’s personal jewels and shows the many ways in which diamonds, the hardest natural material known, have been used and worn by British monarchs over the last two centuries.  Individual diamonds have achieved great renown, passing down the generations and between enemies or allies as potent symbols of sovereignty and as precious gifts.  Many of these extraordinary stones have undergone a number of transformations during their history, having been re-cut or incorporated into new settings as fashions and tastes have changed.

The Cullinan Diamond, which weighed 3,106 carats in its rough state, was discovered at the Premier Mine near Pretoria in South Africa in 1905.  At first the stone was assumed to be a crystal, as it is three times larger than any other diamond that has been discovered.  When it was taken to the mine manager’s office, the clerks threw it out the window, unable to believe that something so big was a diamond.  Eventually they were persuaded, and the diamond was named after the chairman of the mining company, Thomas Cullinan.

Measuring 10.1 x 6.35 x 5.9cm, the diamond was notable for its extraordinary blue-white colour and exceptional purity.  Although it is the largest stone to have ever been found, the rough diamond had a cleavage face on one side, which suggested that it might once have formed part of an even larger stone.  Soon after being discovered, it was sent to London and taken to Buckingham Palace for inspection by King Edward VII.  For the next two years the stone remained a public wonder, during which time it was shown to many prospective clients – although it was hard to find a buyer, as no one could understand how a stone so big could possibly be cut.  Eventually the Prime Minister of the Transvaal suggested that his government should acquire the Cullinan and present it to Edward VII as a token of loyalty, a gift that the King was eventually recommended to take.  So, in 1907, under police protection, the uncut stone was conveyed to Sandringham House in Norfolk, where the King was celebrating his 66th birthday. 

The gift did not include the cost of cutting the stone, and this task was entrusted to the celebrated firm of IJ Asscher of Amsterdam.  No one had ever cut such a huge stone – and the complexities of doing so were many.  It was too large to be cut into a single gem, so cleaving or sawing was necessary.  After weeks of consideration, including four days spent making the groove into which the steel cleaving knife was to be inserted, the stone was ready to be split.  The first blow broke the knife, but the diamond remained intact.  A second cleavage knife was fitted, and this time the blow split the diamond in two.  A few days later, the task of dividing up these two large pieces began.  Eight months of grinding and polishing followed, for three polishers working 14 hours a day.  Eventually, they produced nine principal numbered stones, 96 small brilliants and nine carats of unpolished fragments. The total weight of the gems cut from the Cullinan amounted to 1,055.9 carats.

In 1909, the two largest gems were formally presented to King Edward VII at Windsor Castle.  These are the two largest colourless and flawless cut diamonds in the world.  Today, they are set at the head of the Sovereign’s Sceptre and into the Imperial State Crown.  The other seven, which are reunited in the exhibition, were all mounted by Garrard’s or Carrington’s for Queen Mary in a variety of settings, designed to be adaptable, allowing many possibilities and combinations for the wearer.

Exhibition curator Caroline de Guitaut said, ‘Until 26 January 1905 no one had ever seen a diamond of this size. So incredible was its discovery that the moment it was found at the Premier Mine it was thrown out of the window of the mine manager’s office because it was thought to be a worthless crystal.

‘Now, for the first time, our visitors will be able to see seven of the nine principal stones cut from this magnificent and highly important diamond.’

Tickets and visitor information: or +44 (0)20 7766 7300.

For further information and photographs, please contact the Royal Collection Press Office, +44 (0)20 7839 1377,  A selection of images is also available from

Admission to the State Rooms at Buckingham Palace is managed by the Royal Collection Trust, a registered charity in England and Wales (1016972) and in Scotland (SCO39772).