LONDON.- For years they have been unfairly regarded as the sole preserve of maiden aunts and respectable ladies of a certain vintage.

Now pearls are replacing diamonds as a staple of the fashion set after being championed by The Duchess of Cambridge.

Elegant pearl earrings – as worn by Kate Middleton on last month’s royal tour of Australia and New Zealand – have become a wardrobe must-have overnight.

It’s not just British royalty who are pearl fans. America’s First Lady Michelle Obama is often seen wearing her favourite double stranded pearl necklace and fashion icon Sarah Jessica Parker has long been a fan of pearls. She wore a fabulous strand of pearls at the launch of her pop-up shop in New York in February and regularly accessorizes her outfits with pearls.

Thanks to the Duchess of Cambridge and Sarah Jessica Parker, pearl wearers are becoming younger and classic sets of the gems are being sold for huge sums by one of the world’s leading auction houses.

Bonhams believes natural pearls are now hitting record prices because of their rarity – overfishing and pollution mean the supply of new natural pearls is waning – coupled with the influence of celebrities.

Other pearl fans include singer Katy Perry, Angelina Jolie and Scarlett Johansson.

The Kate Middleton factor – teaming pearls with high-fashion outfits to create a stunning modern classic look - means pearls suddenly have an important new cachet.

The Duchess looked stunning in a set of simple pearl drop earrings visiting Christchurch last month. But it was not the first time Kate has modelled pearls, and her patronage is introducing them to a new generation.

Jean Ghika, head of jewellery in the UK and Europe at Bonhams, said: “Pearls were once seen as a bit dated – perhaps the preserve of an older generation, but we’ve seen a complete change in how they are viewed.

“A younger fashion set is now completely at home wearing classic pearl earrings and you’re as likely to see them in nightclubs and premieres as you are at Ascot or the Epsom Derby.”

Bonhams, which sells more jewellery than any other auction house, says investors are increasingly snapping up rare natural pearls because of their increasing rarity.

Really good examples of natural pearl – based on size, uniform shape, lustre and blemish-free skins – do not appear on the market as often as they used to.

Jean Ghika adds: “They are a rare commodity and it is often very difficult to find good quality examples. Quite simply, the supply of natural pearls is not going to increase.

“Long-term, they will become more of a rarity and therefore even more highly-prized. As a result, pearls that have some age, or were part of a historic collection, can be highly appealing to potential buyers and investors.”

The auction house has recently recorded record sales of natural pearls, including:

• A pair of natural pearl and diamond earrings which sold for £290,500 in April – double their estimate.

• A single natural pearl measuring 11.5mm mounted as a ring, which sold in April for £30,000, ten times the upper estimate

• A long single strand of graduated natural pearls measuring 5.5mm-8.5mm, which sold for £87,600 in April 2012, more than double the pre-sale estimate

For its annual Jewellery in June campaign, Bonhams is inviting people to bring in their jewellery for free auction valuations in a bid to unearth new treasures.

The auction house’s 20 jewellery experts and gemmologists can advise on prices, vintage and even care.