The Duchess of Cambridge's engagement ring has been valued at £300,000 – a tenfold increase from what it was originally valued at in 1981.
The ring, which belonged to Prince William's late mother Princess Diana, was valued at £28,000 when Prince Charles proposed to her with it.
The stunning piece of jewellery, which comprises 14 solitaire diamonds surrounding a 12-carat oval blue Ceylon sapphire and set in white gold, has topped a list of the 20 most famous rings in the world.
"The Duchess of Cambridge's ring has appreciated more quickly than any other ring in the list," jewellery expert Vashi Dominguez said on TV show This Morning.
"It's Kate's quiet confidence to lead as a style icon that makes the ring so special. Symbolically, blue can convey a sense of trust, loyalty and understanding, which is perfectly in tune with the giving of an engagement ring.
"Blue is also a colour associated with the royals, of course, so I believe it's fitting that Kate is wearing a ring to reflect her addition into the family."
It is worth three times more than the Queen's engagement ring. Presented to her by Prince Philip in 1947, Queen Elizabeth's ring – consisting of a three-carat diamond flanked by five smaller diamonds set in platinum — has increased in value from £10,000 to £100,000 today and comes in second place on the list.
Third on the list is Michelle Obama's ring – presented to her by Barack Obama in 1991, when he was an unknown lawyer, it was worth a modest £7,500 then and is now estimated at £20,000.
The value of the top three most famous ring are, however, dwarfed by Beyoncé's engagement ring which was valued at £2.7 million in 2007 when she became engaged to Jay Z and is now valued at a staggering £5.8 million.
The statement piece is an 18-carat diamond set in platinum. It comes 11th on the list.
The second most expensive ring on the list belongs to reality TV star Kim Kardashian. Given to the brunette beauty last year by beau Kanye West, it is priced at £5,150,000.
David and Victoria Beckham are now considered global icons, but when they first became engaged in 1998, the bride and grooms' rings value was a modest £100,000 each.
The rings have both shot up in value to be worth £230,000 each.
Victoria's three-carat pride of joy is marquise cut; an unusual, elegant diamond shape, while David's matching band is set with 96 exquisite diamonds and they both rank as sixth on the list.
"Even in 1998, Victoria’s ring was unusual and perhaps ahead of its time," said Vashi.
"It was a sign that she would turn to fashion and become greatly successful in the industry."
Angelina Jolie's 2012 engagement ring, designed by her fiancé Brad Pitt, features diamonds of the highest quality cut to a size and shape to suit the screen beauty's slender hand. It originally cost £600,000, is now worth £950,000 and comes 12th on the list.
Vashi.com is one of Europe's largest online diamond and jewellery sellers.