Queen Elizabeth is regal in blue to celebrate granddaughter Princess Eugenie's wedding -- and sports an 18.8 carat brooch

Regal in blue!

Queen Elizabeth attended her granddaughter Princess Eugenie's wedding to beau of 7 years Jack Brooksbank on Friday, which took place at Windsor Castle's St. George's Chapel. Her majesty donned a surprisingly muted color of pale blue for the occasion, which was also attended by her husband Prince Philip, 97, Duchess Kate and other members of the royal family.

The creamy blue ensemble was designed by one of her go-to designers Angela Kelly. The 92-year-old monarch dressed up her look with a strand of pearl necklaces, a cream flower and a pair of pearl drop earrings.

See more of Queen Elizabeth at the royal wedding:

The queen also sported a gorgeous diamond brooch from her personal jewelry collection for the big day. The heart-shaped pin, made up of a hefty 18.8 carats, is known as the Cullinan V brooch and has been in the royal family since 1907 after being mined in South Africa. It's considered the largest diamond ever discovered. Goodness.

Also on display from Queen Elizabeth's personal jewelry collection was Eugenie's tiara. The princess, who opted to forgo a veil for her big day, chose the queen's Greville Emerald Tiara, which features a large green emerald surrounded by six smaller ones. Designed in 1919, the tiara was inherited by the queen from Margaret Greville in 1947.

For more on the royal family festivities, watch the video above!

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