A dazzling exhibition of royal gems being staged to mark the Queen's 60-year reign will feature jewellery made from the world's largest diamond.
Photo: Geoff Pugh
The major display will reunite for the first time seven of the nine principal stones cut from the Cullinan Diamond.
The gems are set in brooches, a ring and a necklace, many of which have been worn by the Queen throughout her reign, with the remaining two stones forming part of the Crown Jewels.
In a fitting tribute to the monarch's Diamond Jubilee, the Royal Collection is putting on the celebration of the precious gemstones, charting their association with British monarchs during the last 200 years.
The exhibition, which will be the focal point of Buckingham Palace's 2012 summer opening, will include an unprecedented display of some of the Sovereign's personal jewels.
At the heart of the display are the gems from the Cullinan Diamond, which weighed 3,106 carats in its rough state when discovered at a mine near Pretoria in South Africa in 1905.At first it was thought to be crystal, as it was three times larger than any other diamond that had been found.
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.''
The clerks who had thrown the stone away were eventually persuaded it was a real gem and it was named after the chairman of the mining company, Thomas Cullinan.
In 1909, after it had been cut and polished, the two largest gems hewn from the rough diamond were formally presented to Edward VII.
These are the largest colourless and flawless cut diamonds in the world, with the biggest - the Great Star of Africa - set in the Sovereign's Sceptre and the second gem - the Second Star of Africa - set in the Imperial State Crown. Both are on display at the Tower of London.
Among the items that will go on show at the Palace will be the Girls of Great Britain Tiara which the Queen recently wore at the state banquet for the Turkish president in November.
It was a wedding present to Princess Victoria Mary of Teck, later Queen Mary - the Queen's grandmother - on behalf of the Girls of Great Britain and Ireland in 1893.
Originally crafted with upright pearls around the top and a bandeau base, it was altered in 1920 by Queen Mary, who replaced the pearls with diamonds and removed the base.
It is one of the Queen's favourites and is forever known as ''Granny's tiara'', being a wedding present from her grandmother in 1947. It is said to be very light and easy to wear.
Many of the pieces that will be on display at the Palace have undergone transformations through the ages - having been re-cut or used in new settings depending on the fashion or the preferences of the queens or princesses who used them.
Visitors will also see the impressive necklace and earrings worn by the Queen at her coronation ceremony in Westminster Abbey in 1953.
The collet necklace is formed of 25 large graduated cushion-shaped brilliant-cut diamonds and a central drop-shaped pendant of 22.48 carats.
It was created in 1858 for Queen Victoria - the only other British monarch to celebrate a Diamond Jubilee - from a Garter badge and ceremonial sword.
The impressive detachable diamond drop, known as the Lahore stone, was originally part of the Timur ruby necklace.
Over time the necklace, which was also worn at the coronations of Queen Alexandra and Queen Mary, has been modified.