Whereas once they were seen as outdated and belonging to another generation, the popularity of pearls has soared in recent years after being championed by fashionistas around the world.

Whereas once they were seen as outdated and belonging to another generation, the popularity of pearls has soared in recent years after being championed by fashionistas around the world.

The Kate Middleton factor – teaming pearls with high-fashion outfits to create a stunning modern classic look - means pearls have suddenly made a comeback and are now replacing diamonds as that must-have fashion accessory, according to auction house Bonhams.

In recent months Bonhams has recorded record sales of natural pearls, including a pair of natural pearl and diamond earrings which sold for £290,500 ($486, 634) in April - double their original estimate.

The auction house 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.

The comment about pearls comes at a time when diamonds, jewellery, art and fine wine, as well as classic cars, are talked about as niche alternative investments in an uncertain economic environment. With all these areas, a level of expert knowledge and effort is required to unearth returns.

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

“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,” said Jean Ghika, head of jewellery in the UK and Europe at Bonhams.

Although they are back in vogue, 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, said Ghika.

“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,” she added.