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October babies, let’s face it: you’ve got a pretty cool birthstone. Opals come in a variety of colors, and often they look like they’re literally glowing from within. Most of the world’s opals are mined in Australia, so it’s no surprise that it’s also the country’s national gemstone. Royals have been attracted to opals for centuries, from the “Burning of Troy” opal given by Napoleon to Josephine all the way to the Duchess of Sussex’s engagement earrings, though many royal collections lack major opal pieces. Today, we’re running down ten of the most intriguing opals in royal collections past and present.

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10. Queen Letizia’s Pink Opal Earrings: Letizia’s jewelry collection includes the “Dinah” pink opal earrings from Tous, a Barcelona-based jewelry company. The Spanish queen prefers extremely delicate, minimalist jewelry, so these drop earrings are actually some of the more substantial in her jewelry box.

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9. The Dutch Opal Flower Brooch: The Dutch royal family’s jewel foundation includes a 19th-century flower brooch set with milky opals and a single ruby. Queen Juliana wore the piece during the 1970s, and Princess Beatrix brought it out of the vaults during the final months of her reign for a state visit to Brunei.

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8. The Australian Opal Spray Brooch: Since opals are Australia’s national gemstone, and Elizabeth II is the Queen of Australia, you’d be correct in assuming that her jewelry box included several opals. We recently featured an extensive post on this brooch, which was one of her wedding gifts in 1947. The brooch, given to her by the Returned Sailors’, Soldiers’, and Airmen Imperial League of Australia, features black opals set in gold.

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7. Princess Marie’s Opal Choker Necklace: In the late nineteenth century, Princess Marie d’Orléans, the wife of Prince Valdemar of Denmark, owned a striking parure of jewels set with opals and moonstones. The suite included an era-appropriate choker necklace. A revised version of the necklace today belongs to Chantal d’Orléans, who has loaned it on occasion to her daughter, Kildine Stevenson.

Princess Marie wears the original setting of her opal tiara and choker necklace

6. Princess Marie’s Opal Tiara: The opal tiara from Princess Marie’s parure ended up with her son, Prince Viggo; it was substantially remade to look like a more traditional tiara and worn by his wife, Eleanor. More recently, it was worn by Viggo’s daughter-in-law, the late Countess Ruth of Rosenborg.

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5. The Dutch Fire Opal Suite: Princess Beatrix of the Netherlands has a collection of private jewelry separate from the family’s jewel foundation. It includes a set of fire opal and diamond jewels: a bracelet, a brooch, a ring, and a pair of earrings. Fire opals are an especially appropriate stone for the Dutch royals, as they’re often found in shades of yellow-orange. Beatrix sometimes loans the set to Queen Maxima, who wore them to an awards ceremony last year.

Queen Mercedes of Spain

4. Queen Mercedes’s Opal Ring: Just in time for Halloween, it’s a cursed opal! For their wedding in 1878, King Alfonso XII and Queen Mercedes of Spain were given an opal ring by one of his former mistresses. The story goes that Mercedes (probably not having been clued in about the giver’s former relationship with her husband) wore the ring — and then she died. Alfonso passed along the ring to his grandmother, Queen Maria Cristina — and then she died. Next, he gave the ring to his sister, Infanta Maria del Pilar — and then she died. Eventually Alfonso puts the ring on himself, and you guessed it — he died. Of course, Mercedes had typhoid fever even before her marriage, Maria Cristina was 72, and Alfonso had tuberculosis and dysentery. But maybe it’s for the best that the family reportedly gave the ring to Madrid’s cathedral — you know, just in case.

Queen Alexandra on her wedding day

3. Queen Alexandra’s Opal Suite: When Princess Alexandra of Denmark married the Prince of Wales in 1863, her new mother-in-law, Queen Victoria, gave her a suite of opal and diamond jewels. The set included a cross pendant, a set of three brooches, a pair of earrings, and a bracelet (which Alexandra wore on her wedding day). The late Prince Albert had apparently drawn the designs for the set, which was made by Garrard. But Alexandra was not a fan of opals — a novel by Sir Walter Scott had popularly depicted them as a symbol of bad luck — and some have suggested that she had these pieces reset after Victoria’s death. I’m not sure that’s the case (the sources I have aren’t clear on the pieces’ fates), but either way, Alexandra’s opals don’t seem to be hanging about in royal hands these days.

Queen Victoria wears the opal version of the Oriental Circlet and its coordinating earrings and brooch

2. The Oriental Circlet: Queen Alexandra didn’t stop her opal makeover with her own jewels — she also had other opal pieces in the royal collection reset with Burmese rubies. Among these were Queen Victoria’s Oriental Circlet, designed by Prince Albert and set with opals, one of his favorite gemstones, as well as a necklace and a pair of pendant earrings. All of these formerly-opal jewels remain with the royal family today in their renovated, ruby-set form.

Queen Elizabeth II wears the Andamooka Opal Necklace (The Age)

1. The Andamooka Opals: During her tour of Australia in 1954, Queen Elizabeth II was presented with an astonishing set of opal jewels. The necklace and earrings were set with opals that had been discovered in the Andamooka opal fields; the enormous opal in the necklace weighs more than 200 carats. Elizabeth wore the necklace once during the tour, pairing it with Queen Mary’s Lover’s Knot Tiara — and then put it in the royal vaults. I can see that it’s perhaps not to the Queen’s taste — the necklace especially is an unusual modern piece — but surely there’s someone in the family (*cough* Kate? *cough*) who could take this set out for a spin?