It was a moment of unity for all the nations for whom the British monarch is head of state.

There was, however, more modest symbolism at work that evening, which may not have been obvious to most onlookers. It was powerful symbolism, nonetheless — and it was the Queen’s brooch. This beautiful piece of adornment had never before been seen in public, having been created especially for the occasion of the Jubilee.

Queen Elizabeth II wearing the Platinum Jubilee brooch, from the Goldsmiths’ Company Instagram feed

The Queen is rarely seen without a brooch or pin. Many in her collection hold great meaning, especially those she inherited from Queen Elizabeth the Queen Mother in 2002.

This Platinum Jubilee brooch was commissioned by the Goldsmiths’ Company as a gift to the Queen to mark her Platinum Jubilee and her 70 years of service. The Goldsmiths’ Company invited several leading UK designers to submit designs based on a brief developed by the company and the Queen’s dresser, Angela Kelly. A shortlist of six designs was drawn up by an expert panel selected from members of the Goldsmiths’ Company, and this shortlist was then presented to the Queen.

The final design selected by Her Majesty was one by David Marshall, the award-winning British jewellery designer who has been in the industry for more than 30 years and who, with his team at the London Art Works, are based in Hatton Garden, London. This team included designer Denise Gibbs, CAD designer Simon Wolfberg, diamond mounters Matt Martin and Madeline Rowe, and diamond setters Craig Michel and Mark Moutia; and the techniques they employed included both the traditional lost-wax-casting process as well as the more contemporary computer-aided design.

But what of the brooch? It is made up of seven diamond-set bands representing each decade of the Queen’s reign. Decoratively, it features the rose, the thistle, the daffodil and the shamrock – national flowers of the UK’s four nations. A lily of the valley flower also blooms from the bands. Not only is it one of the Queen’s favourite flowers, it was part of her 1953 Coronation bouquet. The lily of the valley stem was a special addition to the original design at the behest of the Palace.

Marks on the brooch were applied by the 700-year-old Goldsmiths’ Company Assay Office. Photography by Clarissa Bruce

The brooch is made of 18-carat white gold, platinum, 97 round brilliant-cut diamonds (2.50 carat) and seven fancy-cut diamonds (0.40 carat). On its reverse, it is laser-hallmarked with the commemorative Platinum Jubilee mark as well as the Leopard’s Head mark, showing that it has been hallmarked in London. Appropriately, the marks were applied by the 700-year-old Goldsmiths’ Company Assay Office.

So extensive is the Queen’s collection of brooches it is difficult to say when it might be seen again, but a duplicate brooch was made (though with different marks) for the Goldsmiths’ Company collection, and will be on display in autumn at the Goldsmiths’ Fair.

MAIN IMAGE of the Jubilee Beacon at Findern, Derbyshire by Jason Thompson/Unsplash; brooch photography by Clarissa Bruce