Rock on: How celebrity jeweller Stephen Webster transformed the image of bling

Mind yer head," says Stephen Webster, indicating the low-hung chandelier with the giant crystal globes, "Mickey Rourke bashed 'is head on that, an' I thought 'e was done for." We are closeted together in the tiny buyer's boudoir at Webster's flagship store in Mayfair, surrounded by photographs of his devoted clients: Kate, Sienna, Madonna, Sharon, Jennifer... If the plush sofa in here could talk, it would purr for hours about the fabulousness of the celebrities that have perched on it, discussing gems with Mr Webster.

For he is the cool-jewels Kaiser. He puts the rocks in rock'n'roll. Over the years he has carved out a reputation as a jeweller of consummate skill and flair who, when not in his workshop with lens and polisher, comes on like a rock deity. Originally from Kent, he affects a Cockney f swagger that would not disgrace a Pearly King. He swans about in a frock coat by Vivienne Westwood. He roars about on a Harley Davidson. He takes road trips around America in his beloved 1959 Thunderbird. He owns a Beretta shotgun ("I got a licence for it. It's not sawn-off or nothin'..."). Facially he resembles Bob Dylan ("Yeah, I get Bob Dylan a lot") with a bit of the young Keith Richards thrown in. He lunches with Harvey Weinstein. His clients are wayyyy beyond fashion and music royalty (even Royal royalty): he designed the wedding bands for Madonna and Guy Ritchie, and has made one-off items for Ozzy Osbourne, Johnny Depp, Axl Rose, Cameron Diaz, Kate Beckinsale, Sharon Stone and Charlize Theron. Possibly as a consequence, he's a chronic name-dropper. He'll mention, in his camp-street-trader voice, that he once interviewed Mick Jagger for Rolling Stone, that his friend Bryan Ferry is going with him to Baku, and that Christina Aguilera sang at his 50th birthday.

He may sound an insufferable wannabe, but meeting him is a pleasure. His eyes sparkle with delight at how busy his life has become. Stories of celebrity excess tumble from his lips. And success has clearly arrested the ageing process for Mr Webster. For our interview he is dressed in down-with-the-kids grey T-shirt and skinny cardigan. His jeans are unfeasibly tight for a man of his years (52). His curly hair is suspiciously dark. Four steel-and-ceramic bracelets encircle his wrist.

You wonder: can this raucous popinjay can really be the man behind those sublime Webster productions – these birds and beetles, skulls, spiders and exotic fish in white gold, fire opal, green agate and black mother of pearl – worn by Kate Moss, Halle Berry and Jessica Alba? Yes he can. He invented Crystal Haze, a dream of faceted quartz crystal set over a layer of natural precious stone to produce a sea-blue-shimmery, holographic effect. The crab and lobster rings from his Jewels Verne range (nice pun) made from white gold, diamonds, quartz and sapphire or coral, went down a storm in Eastern Europe. "Russians went crazy for it. I said, 'Why d'you like the crab?' They said, 'We love everything about it. It's dark. It's got this wonderful gemstone. And... it's a crab.' I can't understand the appeal until my wife puts one on, and then it makes sense." There's nothing crab-like about his wife Anastasia, a tall, beautiful Russian, 40 this year and mother of Amy and Nika, but she makes a wonderful setting for the sapphires and black opals on this sparkling crustacean.

Like a conscientious rock god, Webster is always travelling, to jewel-launch events and diamond mines. His launch gigs are legendary. When his roadshow rolls into town, nobody is safe. "Jewellery events can be deadly – like, 'Here's some champagne, here's some jewels'. We can't do that," he growled. "Some time ago we started making them real events. They've grown and grown until people expect a really good night out." And they get it. The centrepiece is usually a spectacular, alcohol-drenched party, with bikers, naked girls and wanton misbehaviour. When they opened a store in Ekaterinburg, Siberia, Webster was driven from the airport through the freezing night in a stretch Hummer with two log fires inside.

Last month he was in Washington DC, Moscow, Belfast and Baku, Azerbaijan, showing off his new line of femme-fatale bijoux. "I got this collection called 'It Started With Eve'," he explains, "rings inspired either by mythological or real women who were killers or up to no good. I got Lady Macbeth, Bonnie Parker, the Girl with the Golden Gun, Eve... They're more than rings, they're limited-edition little sculptures, and you can't expect people to part with their money [the fabulous Eve ring costs $29,000] without creating something around them. So I wrote a murder mystery."

You what? "We tried it out first in Harrods, they said it was the most extraordinary jewellery event they'd ever had. People come in and realise they've entered the scene of a crime. There's a dead person lyin' on the carpet with a Christian Louboutin heel sticking in his chest and there's blood everywhere. And you meet the posse of women who look after him – his driver, his maid, his chef, his mixologist – one of them killed the guy, and any one could have done it." He chuckled. "When we started, we used mannequins from Harrods. Then Zandra Rhodes came to help, and we started using a real guy. It freaks people out, as there's a real person laying there with a shoe in his chest and blood all over his shirt, not a model any more..."

He is not, you may have gathered, your run-of-the mill jeweller, if your notion of a jeweller is a chap in brown overalls with a lens screwed into his eye and a pair of tweezers in his hand. Along with his friend Theo Fennell, six years his senior, Webster has rebranded the jeweller as an artist rather than an artisan, a chap of flair and wild imagination rather than just the ability to attach diamonds to sapphires on a circlet of gold.

Webster talks about his creations with cooing fondness, as if discussing old girlfriends. "See this? Red tourmaline. You can't buy them any more because the mine ran out. A lot of tourmaline was mined in Brazil, but all the red ones were from just one place and now they're gone." He shook his head sadly. Earlier this year he visited Peru as an ambassador for Fairtrade. "All my engagement rings are made of Fairtrade gold, and I went to see what life was like for a Peruvian artisanal miner. How awful it can be. I went with my brother, an' it was an incredible experience. The people who migrate to these mines earn two dollars a day, yet they're mining gold, which is $1,600 an ounce. There were moments on the trip that were very emotional. The people at the coal face, bringing it out, that was the worst of the worst. You stand there and think, Fucking hell, how lucky are we?"

Webster didn't have the luckiest start in life. Born in Gravesend, his father Tom was a draughtsman and his mother Jean a housewife with a flair for cake-baking. Outside the family home, youths could often be found scrapping in the street. They didn't take kindly to the swaggeringly independent Webster with his dyed-blue barnet. At the local grammar school he failed to shine, but secured a place at Medway College at 16, studying jewellery design. After two years with the designer jeweller, John Donald, he went solo – disastrously.

"The minute I finished my apprenticeship, I was out. I wanted to be the best craftsman, I could make pretty much anything, but I didn't have customers, so I ended up working for the trade, working all day for £10. Then I met this Canadian offering £30,000 a year for a 'complete jeweller all-rounder'. I didn't know what that was, but I put my hand up. He flew me to Canada – I'd never been on a plane before – and I landed in Alberta, in a fucking ski resort." He laughs. "This was the guy who introduced me to gemstones. He was a gem adventurer, like Indiana Jones – he'd bugger off up the Khyber Pass, then pop up in Brazil and Africa, and come back with stones I'd never heard of, like tanzanites and tourmalines." It was a perfect education for Webster. "Because the guy used to come back with these frigging great gems, and you could not put them into small jewellery items. They had to be big. That's when I started to study and understand more about gems and really love them. I knew I could give people something exciting, that I'd never have been able to do if I'd been making three-stone diamond rings for the trade."

Now he receives A-list commissions from all over the world. "I've done this so long, I'm not at all intimidated, no matter who it is. But I'm amazed by how much some people know. Madonna is a perfect example. She knew exactly what she wanted for Guy. When David Walliams and Lara Stone came in looking for wedding rings, she knew he wanted something more than a band, but he didn't know what he wanted until I showed him some gun-engravings." Among his current bespoke work is a necklace for a woman in New York who admired a previous Webster bijou. He sent her his new design, to keep. "You have to make the effort, because the piece she liked cost £120,000. I send her the artwork as a bonus."

Had the jewellery world become muddied by the introduction of semi-precious and even fake stones? "What, like zircon? You know there's real zircon and there's synthetic cubic zirconia, which is created as a fake diamond and made in a lab? I find myself dealing more and more with stuff other than rubies and sapphires and diamonds and emeralds? Because I'm not Laurence Graff [the Stepney-born British jeweller who made billions by selling rare jewels to sheikhs and sultans] and that's not my world. I love the sparkle you get in a diamond, but it doesn't do anything for me, whereas" – he glanced at the treasure trove of gems on his shops' angular glass display cabinet – "this peridot from Pakistan, that's amazing. I just think wow, that came out of the earth."

Are there new rules about what's precious and what's not? "Those rules've gone out the window," said Webster. "You can't apply them any more. The rule was that ruby, emerald, diamond and sapphire, they were precious, everything else was semi-precious. In them days, semi-precious meant cheap, the stones weren't really valued, but they are now. Now the conversation goes, 'What's that?' It's a tourmaline. 'Is it semi-precious?' Yeah. 'How much?' A hundred grand. 'How semi-precious is that?' Even in the Crown Jewels, there's a gem that everyone thought for years was a ruby. But it's a spinel, which is supposed to be semi-precious. It's not – it's precious."

In December 2008, Webster was signed up as creative director of Garrard, the world's oldest jewellery house. Venerable bijoutier meets tight-denimed young Turk. Had they watched his rise with horror? "No no. When I first came back from the States in the late 1980s, there was no place for my stuff. Jewellers looked at it and said, 'Well, it's not pearls, it's not wedding rings, it's not engagement rings, it's not cufflinks, what is it? Where does it fit?' But I'd show the guys at Garrards what I was doing and they were incredibly enthusiastic and in 1996 they gave me a one-man show. So I stayed close to them until they were destroyed – when Prince Jefri [of Brunei] bought Asprey & Garrard and closed Garrard."

Webster was called in to make the brand more contemporary. "It took me a while to get used to it," he says. "We're still finding where we fit best. Right now, in London, it's very, very difficult. The economies of Europe are not in good shape. My clients are all international. Historically, Garrards always had a very strong middle-eastern business, and we're getting back into it."

Which leaves him with the problem of how to attract young customers who aren't millionaires or nabobs. "What I wanna offer," he rasped, "isn't a diffusion range, or keyrings and cufflinks, but proper jewellery that I feel is part of our DNA, but that lets more people in." He's experimented with silver plate, with ceramic-coated steel, with (though it's not a word you ever hear on his lips) cheaper materials, selling the results to fashion and concept stores. He's never been busier. "My biggest clients are Saks and Niemens, and believe me, it's two different worlds, precious jewellery and designer jewellery." Now he's being asked to curate a jewellery group for Paris Fashion Week, then London...

If someone on an ordinary salary wanted to buy their girlfriend an engagement ring, could he truthfully say, Don't be scared, we're not Aspreys or Tiffany's, come and get something nice for a few hundred quid? "You've hit the nail on the head there. That's our next job – making people know that walking through our door isn't the most scary thing. Somebody'll be able to tell us how to communicate that without devaluing the name."

The last thing I want to know, I said, is the rock'n'roll obsession. When did it start? Why didn't you choose the music rather than the gems? "When I was at school, at 16, it was glam rock. It's always stayed with me. I'm a glam-rock star. Why am I taking Bryan Ferry to Azerbaijan? Because of Roxy Music. And David Bowie. And Marc Bolan. Theirs were the first records I bought. And I had two years of guitar lessons, from the first person to get a degree in pop music. He was offered a job in California. Before he left he said to me, 'You know you're never going to be able to play that, don't you?'"

He laughed uproariously. "I'm hopeless on the guitar. I've got some nice guitars I've swapped with people for jewellery. I got a Fender Stratocaster from Robert Cray, one of his own. People expect me to pick one up and jam, but I can't. I'm a complete fake. But I got a lot of friends who want to teach me. The latest is Chrissie Hynde. She says, 'Look at British guitarists – do they look like the smartest people in the world? No. Some of them can't look after themselves, but they can play.' And she says, 'I will teach you.' So that's all right, innit?" And Mr Webster goes off into peals of delight at the way the celebrity world has beaten a path to his jewelled and glittering door.