Empress Farah of Iran wore the Noor-ol-Ain tiara when she married Mohammad Reza Shah Pahlavi, the last Shah of Iran, in 1959. Meaning “light of the eye”, the tiara was made by Harry Winston using the 60-carat Noor-ol-Ain diamond, one of the rarest and largest pink gems in the world. It also has 324 other pink, yellow, and colourless diamonds, set in platinum, per Jeweller Magazine.

The Persian empress wore the tiara regularly for royal events during her husband’s remaining years on the throne. After the 1979 revolution, it belonged to the state and is reportedly on display at the National Jewels Museum in the basement of the Central Bank of Iran.

9. Queen Mary I’s Cartier La Peregrina pearl – US$11.8 million

La Peregrina pearl, meaning “The Pilgrim” or “The Wanderer”, has travelled all over the world since it was discovered in the Gulf of Panama in the 16th century. It first belonged to Queen Mary I of England as a gift from her future husband King Philip II of Spain, according to an article on Medium.

After her death, the jewel was returned to Spain and worn by several queens before landing in the hands of historical figures like Napoleon Bonaparte’s brother Joseph who ruled Spain in the early 19th century, and later Elizabeth Taylor as an auction gift from her husband.

The Hollywood star asked Cartier to redesign it in a necklace of pearls, diamonds and rubies, according to Christie’s. After her death, it was sold at the auction house in 2011 for a record US$11.8 million.

8. Queen Sonja of Norway’s Garrard diamond tiara – US$12 million

Among the tiaras in the possession of Queen Sonja of Norway, the piece originally inherited from Queen Maud is the most interesting – because it’s a replica.

In 1995, it was stolen on its way to Garrard for valuation and maintenance. Never recovered, Garrard eventually made a replica to replace the stolen original. Its value is estimated to be about US$12 million today.

7. Princess Eugenie’s Boucheron emerald Kokoshnik tiara – US$12 million

It was created in 1919 by the French luxury jeweller Boucheron for British socialite Dame Margaret Greville, who gave it to the queen mother later. Resembling an old “Kokoshnik” Russian headdress, the tiara is made of rose-cut pavé diamonds set in platinum with six emeralds on either side, according to the royal family’s website.

Queen Elizabeth inherited the tiara following her mother’s death in 2002 and added it to her royal tiara collection, but never wore it in public.

6. Princess Diana’s Garrard ‘Swan Lake’ Suite – US$12.1 million

The Swan Lake necklace was named after Princess Diana, who wore it to the ballet at London’s Royal Albert Hall in 1997 shortly before her tragic death, and it became the most valuable piece in her extensive jewellery collection.

It was created by Garrard, then the Crown Jeweller, with 178 diamonds and five pearls, according to British media. A pair of earrings were also made to complete the suite but Diana didn’t have the opportunity to wear them. The Swan Lake Suite was then sold at New York auction house Guernsey to a Ukrainian couple for US$632,000 in 2010. More recently, the same couple have asked for US$12.1 million for the piece, according to The Court Jeweller.

5. Princess Katharina Henckel von Donnersmarck’s tiara – US$12.7 million

The tiara was commissioned in the 1900s, possibly from Chaumet, by German Prince Guido Henckel von Donnersmarck (1830-1916) for his second wife, Russian aristocrat Katharina Slepzow, according to Sotheby’s.

It features 11 large pear-shaped emeralds of up to around 500 carats all together. Its base has a series of large cushion-cut diamonds resting atop a row of diamond laurels set in silver and gold. It was sold at Sotheby’s for the first time in 1979 and later in 2011 at a record auction bid for a tiara at US$12.7 million.

4. Kate Middleton’s Delhi Durbar emerald choker – US$20 million

The queen asked Garrard to remodel it in 14 emeralds and brilliant-cut diamonds mounted on platinum. Later, it was given to Princess Diana as a wedding gift from Queen Elizabeth and she wore it a couple of times. It’s believed to be worth around US$20 million today according to Regal Fille.

3. Queen Elizabeth’s Cartier Williamson diamond brooch – US$30.5 million

Completed in the queen’s coronation year, 1953, the piece was worn by her at important occasions, like family portraits, the weddings of Prince Charles and Princess Diana in 1981 and Prince Edward and Sophie in 1999, as well as at the meeting with former President Obama in 2009.

2. Queen Elizabeth’s Granny’s Chips brooch – US$61 million

The two enormous Cullinan diamonds – the III and IV – were part of a collection cut from a diamond found in Cullinan, South Africa, and were a gift from the South African government to Queen Mary. Weighing 3106 carats, it was the biggest diamond that had ever been discovered in the early 20th century, according to gem consultant Rui Galopim de Carvalho.

1. Kate Middleton’s Cartier Nizam of Hyderabad necklace – US$80 million

The most valuable royal piece is known as the Nizam of Hyderabad necklace. It was a wedding gift to the queen (then Princess Elizabeth) from the Nizam of Hyderabad in 1947, according to Regal Fille.