19 Photos of Queen Elizabeth, Princess Diana, and Kate Middleton in Amethyst Jewels

The Windsor vault's most important purple stones are the Kent Amethysts. They are also among the oldest gems in the royal collection, having originally belonged to Queen Victoria's mother, the Duchess of Kent, who had them made sometime during the first half of the 19th century. When Victoria inherited the set (which, along with the necklace, brooch, and earrings seen here on Queen Elizabeth in 1985 also includes two more brooches and a pair of hair combs), she designated them heirlooms of the crown.

Princess Diana stunned in a monochromatic ensemble for a gala in Chicago in the summer of 1996. To complement her purple Versace gown, the statuesque style icon opted for diamond and amethyst drop earrings, a bracelet featuring three strands of polished amethyst beads held together by an oval amethyst clasp surrounded by diamonds, and a ruby-flecked multi-strand pearl choker.

In 1987, Princess Diana attended the opera in Munich in a Catherine Walker gown, which she accessorized with her diamond and amethyst drop earrings and a double-strand choker of amethysts and diamonds that matches the bracelet above.

For the London premiere of Skyfall in 2012, Camilla, Duchess of Cornwall, paired her own amethyst and diamond earrings with a diamond, pearl, and amethyst sautoir held together by a striking heart-shaped amethyst pendant that once belonged to the Queen Mother, who, in 1923, had received the piece as a wedding gift from her grandmother-in-law, Queen Alexandra.

Just as not all sapphires are blue, not all amethysts are purple. Kate Middleton is particularly fond of her custom green amethyst earrings designed by one of her favorite jewelers, Kiki McDonough, which she debuted for Christmas Day services at Sandringham in 2011. (Rumor has it they were a Christmas gift from Prince William.)

For 2016's Royal Ascot, Princess Michael of Kent wore an amethyst pansy brooch to complement her powder blue look.

While Queen Elizabeth is rarely seen wearing the full Kent Amethyst Demi-Parure, she does often wear one of the brooches from the suite, namely this diamond and amethyst pin featuring three removable amethyst pendant drops that the monarch chose for her meeting with President George Bush during her tour of America in 1991.

For an event during her official visit to Bhutan in 2016, the Duchess of Cambridge wore a pair of lavender amethyst and diamond drop earrings by Kiki McDonough.

For a charity event in 1987, Princess Diana paired her satin and velvet Catherine Walker gown with a giant crucifix, fashioned in diamonds and amethysts and suspended on a rope of pearls, that was on loan for the evening from the House of Garrard.

Though she would never get to assume the title of queen, Wallis Simpson amassed a jewelry collection to rival that of England's grandest monarchs. Oversized brooches and her 19.77-carat emerald Cartier engagement ring from the Duke of Windsor were among her signatures, as was this stunning amethyst, turquoise, and diamond bib necklace (the suite, which included earrings and a bracelet, was also designed by Cartier).

Ever one to color-coordinate her jewels to her wardrobe, Queen Elizabeth again chose the amethyst and diamond brooch from the Kent suite for her 1992 visit to Norfolk on the 40th anniversary of her accession to the throne.

Queen Elizabeth was photographed with her horse "Estimate" at Royal Ascot in 2013, wearing the brooch from her Kent Demi-Parure, this time without the three pendant drops.

The Duchess of Cornwall, noted for both her love of amethysts and an impressive brooch collection, wore a pair of amethyst and yellow enamel pansy brooches for a visit to Greenwich, England in 2019.

The Duchess of Cambridge was photographed in 2014 wearing another pair of green amethyst earrings by Kiki McDonough.

Queen Alexandra, consort of King Edward VII and Queen Elizabeth's great-grandmother, was known for her love of amethysts (see: the heart-shaped amethyst pendant and sautoir she gifted her granddaughter-in-law, the future Queen Mother, above, on Camilla). She famously possessed a Diamond and Amethyst Tiara, pictured here, which she received as a gift from her brother-in-law, Tsar Alexander III of Russia. Unfortunately, after being passed down a few generations, the heirloom was eventually sold by Alexandra's great-grandson, the 3rd Duke of Fife.

Though she has two coordinating amethyst and diamond floral motif brooches set in yellow gold, the queen rarely, if ever, wears both of them together. Here, she opted for one for the opening of a new hospital in London in 2020.

And back in 2012, Queen Elizabeth wore the other corresponding brooch in the set, during her Diamond Jubilee Tour of England.

This three-stranded pearl necklace, which features a clasp of diamonds surrounding a small amethyst, was a frequent go-to piece for Camilla in the early 2000s. She chose it for her first-ever official appearance in 2002, and again for the party to celebrate her engagement to Prince Charles (pictured here in 2005).

In the years since, the Duchess of Cornwall has upgraded to a larger version of her pearl and amethyst necklace, this time with four strands centered with an amethyst clasp with a diamond in its center. She paired it with her amethyst and diamond earrings for an event in 2019.