Women are no longer waiting for men to shower them with gems

Who buys the jewellery? It's a new indicator of who-wears-the-pants in a household. Jewellery has traditionally been something gifted to women and even now that view holds strong: at a recent Business of Luxury summit, Johann Rupert, chairman of Richemont (whose group includes Cartier and Van Cleef & Arpels) talked about fine jewellery as something a man might want to give his wife or mistress. But many women have given up waiting for baubles and are gleefully buying jewellery for themselves – for the fun of it, for investment purposes, as divorce presents, or as a beautiful way to squander their bonuses.

A recent study by Mintel showed that more than half the 2,000 women surveyed bought jewellery simply to treat themselves – admittedly this group, dubbed the "Just Becausers", were predominantly professionals aged 45 and over, with a disposable household income of more than 90,000, but still. Now not only are they buying it for themselves but they are doing so at auction, which traditionally has been the stronghold of male trade buyers.

This news comes from Bonhams, the auction house, which sells more jewellery lots each year than any other international auction house and reports that at its most recent jewellery sales in Knightsbridge, London, half the buyers were women.

The trend is global; in the US, Bonhams expects one-third of its jewellery buyers this year to be female, while in Hong Kong, the figure is already 41%. The numbers are increasing year on year, according to Jean Ghika, head of the Bonhams jewellery team for Europe.

"More people see auctions as a good way to buy vintage, one-off jewellery and we've seen a big increase in female buyers who are buying jewellery for themselves," she says. "These are career women who have successful jobs, who have their own money and are happy to choose their own jewellery with it – sometimes they are spending their bonus on a tangible asset, sometimes they are just treating themselves."

There are the divorce presents to themselves (yes, really), the stuff to show a colleague you've had a bigger pay rise than she has, or jewellery you can exercise in – Bonhams has been briefed to field all these requests and more by high-flying women who appreciate the advantages of auction-buying: individual pieces without the high-street mark-up. But ooh, the auction room! Isn't that enough to strike fear into the boldest boardroom maven? "I know people are frightened of auctions," says Maria Clarke, one of the women buying jewellery at auction. "They think it's like on the television, you scratch your nose and all of a sudden you are bidding, or you will buy a fake and have no recourse. That's not how it works. You have proper guarantees. I've seen people raise their hands and the auctioneer thinks they are bidding, but he asks them, and if they're not, they just say so."

Clarke, who trained as a lawyer before running a private German bank, has fearlessly purchased engagement rings for other people, watches for her husband and son and also uses the process to add to her collection of Fabergé jewellery. "It's fun to look for unique pieces that no one else will have," she says. "It's the chase."

Who wears the pants in her household? Surely we don't even need to ask.

What could you buy?

Bonhams next jewellery sale is on 15 July, in London's Knightsbridge; the catalogue isn't up yet but recent sales included some gorgeous rings – a square-cut emerald surrounded by diamonds which went for €9,593, and an impressively huge rectangular single-stone diamond from around 1950 that was sold for €52,500, including the premium. Ah yes, the premium – new bidders need to be aware of that; the buyer's premium is an additional 25% of the hammer price for the first €70,000 – so factor that in when deciding your limits.