But some of the brooches in the collection barely saw the light of day, with the late queen only showcasing them out in public a handful of times.

This particular brooch is thought to be originally owned by Queen Mary of Teck, who was photographed wearing it in the early 1900’s, according to royal fan account British Royal Jewels stated on Instagram.

Camilla arrived at Windsor Castle wearing the brooch pinned to her black cape, which was stylishly draped over her shoulders

Queen Elizabeth rarely wore the brooch out. Here she is pictured wearing it in 1997 at the Royal Windsor Horse Show

The stylish brooch has sapphires, diamonds and emeralds encased in it

It is believed that Queen Mary went on to wear it for several occasions, including in 1909, after the Royal Family was joined by Tsar Nicholas II and his family for the Cowes Regatta, Tatler reported.

Less than a decade later in 1918, the Bolsheviks assassinated Tsar Nicholas II, his wife Alexandra and their five children, bringing the Russian monarchy to an end.

The brooch paired well with Queen Camilla’s emerald green ensemble that she wore to the annual Easter Mattins service on Sunday.

She put on a show of sartorial solidarity with Sarah Ferguson and Princess Anne, as they all donned shades of traditional Easter green.

The royal looked elegant in her elegant dress which she paired with a coordinating hat, black suede knee high boots and a classic Chanel clutch bag.

Queen Camilla wore a number of brooches, with deep meanings behind them as she put on a brave face and undertook royal duties in the absence of Kate and Charles last week.

Queen Mary of Teck is pictured in 1909 wearing the brooch during the regatta

Elizabeth is pictured wearing the brooch, thought to be originally owned by Queen Mary of Teck, in 1997

Last Wednesday, she made a royal visit to Shrewsbury, where she donned a brooch that has otherwise never been seen in public before.

Camilla was dressed in a brown leopard print blouse by Fiona Clare, a brown suede skirt and camel top stitch coat by Anna Valentine.

She showcase two  bumble bee brooches, one of her own and one belonging to mother-in-law, Queen Elizabeth.

According to The Queen’s Jewels by Leslie Field, one of Elizabeth’s first brooches was a diamond bee brooch set.