Diamonds are forever! How necklace given to Princess Alexandra to mark her 1863 wedding was loved by Queen Elizabeth – and Camilla wore it at the State Opening of Parliament (on her birthday)

The festive opening of the Parliament Building last month was a special day for Queen Camilla in more ways than one.

Not only was it one of the most high-profile events of the year, it was also Her Majesty’s 77th birthday.

Given the majestic event, both she and King Charles were dressed to impress.

While His Majesty wore the Imperial State Crown, it was Camilla who stood out in the Diamond Diadem, along with Queen Alexandra’s Collet necklace.

The last piece is set with 31 cut diamonds from the Golconda mine in India.

Queen Elizabeth II inherited the antique copy and wore it on several occasions, including during a royal tour of Canada in 2010.

According to the encyclopedic book The Queen’s Diamonds by Hugh Roberts, this remarkable piece of jewelry (and the pair of earrings that form part of the demi-parure) were given to Alexandra by the City of London Corporation when she married Bertie, Prince of Wales – later Edward VII – in March 1863.

Despite being hand-cut, the diamonds are as beautiful as anything cut today. “Old mine cut diamonds are a beautiful representation of the art of diamond cutting in the 19th century,” says Grant Mobley, jewelry editor for the Natural Diamond Council in New York.

Her collet necklace could be worn as a choker and was given to the Danish princess by the City of London Corporation on her marriage to Bertie, the future Edward VII, in 1863.

“They reflect a time when cutting was a true craft, performed by nothing more than an artist’s vision of the rough diamond.”

Five of the diamonds were detachable, allowing Alexandra to wear the piece as a choker, either loose or on a velvet ribbon.

She often wore chokers or dog collars with diamonds to hide a small scar on her neck that she received as a child.

The Diamond Diadem, also known as the State Diadem, was designed to commemorate the coronation of King George IV in 1821.

It was subsequently worn (and slightly modified) by queens, both reigning and consort, including Queen Elizabeth II, who first wore it at the official opening of Parliament House in 1952.

Queen Elizabeth II, wearing her State Diadem, on her way to Westminster to lead the first State Opening of Parliament since her accession to the throne in 1952.

Queen Elizabeth on her way to Westminster Abbey for her coronation ceremony in 1953

The diamond Collet Necklace, worn by Queen Camilla, is set with 31 graduated old-mine cut Golconda diamonds and the stunning diamond earrings, also worn on her birthday, were part of what has become known as the Modern Diamond Suite

The Queen wore the Collet diamond necklace when she visited the Royal York Hotel in Toronto, Canada, in 2010 for a dinner hosted in her honour by the Canadian government

She wore it again the following year, just before her own coronation, and then once more as she traveled to all the state openings during her 70-year reign.

It is set with 1,333 diamonds, including a beautiful cross on the front, with two bands of pearls surrounding the diadem.

It is best known because its outline appears on postage stamps as part of the Queen’s silhouette.

On her birthday, Camilla also wore a stunning pair of diamond earrings, part of what has become known as the ‘Modern Diamond Suite’.

It was made from diamonds that were originally set in a tiara Charles bought at auction in 2005.

It consists of a necklace, set with marquise and oval diamonds, from which pear-shaped diamonds hang; and a pair of earrings with a waterfall of pear-shaped diamonds.

But the Queen does not have pierced ears. She told British Vogue in 2023: ‘… nothing goes through my ears.’

That means she has to wear clip-ons. I imagine most of the Royal Collection earrings can’t be adjusted, so she wears them quite often with different jewels.

Camilla’s outing at the State Opening proved that from old to new, diamonds really are forever – and a girl’s best birthday friend!