How Julia Castelli became 'the Sherlock Holmes of diamonds'

Tasked with sourcing some of the most prized gems in the world for private clients, the jewellery expert prides herself on 'solving puzzles and finding solutions'

Jewellery expert Julia Castelli at the Franklin Hotel in Knightsbridge, London. Rob Greig / The National
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Standing in the discreet first-floor showroom of Chaumet’s flagship store in an exclusive corner of London’s West End, Julia Castelli, 46, is in her element.

Surrounded by a glittering selection of tiaras, necklaces, rings and diamonds worth millions of dollars, she tries on different pieces, looks in the mirror and holds them up to the natural light that pours in through the huge floor-to-ceiling windows of the exquisitely refurbished Georgian premises.

Under the watchful eye of the manager, a succession of staff breeze back and forth with sparkling items spread out on black velvet cushions. It starts to become clear just why Castelli has earned the sobriquet, the queen of diamonds.

Castelli operates in the rarefied world of high-net-worth individuals who have the means, but perhaps not the time nor the inclination to find that perfect gift. She is the go-to person for the world’s super wealthy, a one-woman business who is on call 24 hours a day. Whether it is jewels, fine art, fashion or even a thoroughbred racehorse, she can track it down.

Her phone is never off and she is on speed dial for elite clients around the globe. Their identity remains a secret. Utter discretion and loyalty are the name of the game in her business. Without that, her reputation would soon collapse.

“I see myself as the Sherlock Holmes of diamonds,” Castelli says with a smile. “I am solving puzzles and finding solutions for my clients. A client will come to me and say they want something particular. And I go and source it. I don’t hold any stock, so I work on bespoke orders and sourcing. That is my speciality. I know where to find rare, unique things.”

Those clients come from America, Europe, the Far East and, increasingly, the Middle East. “I love working with Middle Eastern customers. They know beauty, they know quality and they have the means.

“They can be demanding and ask for special prices, but I enjoy the challenge. I work throughout the region but with the biggest focus on Dubai.”

So important is this market for Castelli that she is in the process of setting up a company here. “I know the place and have good connections. The plan is by the end of this year to have a bigger presence there. I will be there much more. I want to learn more about the other Emirates. They love and appreciate what I source,” she says.

“I love my trips to that part of the world. The people are so warm and hospitable, service is impeccable and luxury is just next level. I get some of my most unusual and most valuable requests for sourcing jewellery and anything luxury from my UAE clients. They just love anything; the best, the biggest or to have something no one else has in the world. That is my speciality.”

Clients from the Emirates have provided her with some of her biggest and most lucrative challenges. “A recent request from the Middle East was to find two matching diamonds for earrings,” she reveals.

“They had to be 20 carat each, D [the highest colour grade] and flawless. It took me two weeks to find the stones. It can be quite stressful and you have to be very careful who you ask and when. The client was very happy.”

There has been a shift in the profile of Middle Eastern buyers, she notes. “Apparently in the 1990s, money was no object. Now there is a new wave of wealth, and knowledgeable, highly educated clients who know what they like and know what they want. It is a very happening place.”

This world of glitz and glamour is a far cry from Castelli’s upbringing. She was born in a small village in Bulgaria and is half Bulgarian and half Russian. As a child, her yearning for the good life was fired by reading Danielle Steele novels.

These invariably featured successful, independent American women making their own money, and flying between the East and West coasts. “I must have imagined it very vividly because, looking back, I’ve managed to do just that,” says Castelli, who speaks five languages.

With a degree in economics, she was all set for a career in banking in the US. However, when she arrived in New York in 2001 at the age of 25, fate intervened. “While I was finding my feet, I worked in a Russian Jewish jewellery boutique on Madison Avenue. I didn’t have any experience but the family really liked me,” she recalls.

She was smitten by the sparkling world she began to inhabit. A job with Saks on Fifth Avenue selling costume jewellery followed, then another with Chopard. “I have an entrepreneurial spirit. I started organising events for the Russian-speaking community in New York and went on Russian television.”

She became something of a celebrity herself. Then she fell in love with an Englishman and, in 2005, moved to London. Castelli wanted to start a family and knew that working for a company full time would be incompatible.

Her husband, from whom she is now divorced, suggested that she set up on her own, providing a bespoke lifestyle service not just in jewels, but accessories and travel.

In trepidation she picked up the phone, secured her first commission and hasn’t looked back. Life is now a whirl of planes, airports, events and luxury brands.

Her website for Julia Castelli Lifestyle Management features the strapline “A Life Beyond Luxury For You”, but her business really runs on word of mouth recommendations. “I have a passion for sales, jewellery and beautiful things. I am never pushy. It is me transmitting my love and passion for what it is to the client. And listening to their needs and wants.

“I am very fortunate to work with the best of the best, red diamonds, blue diamonds, green diamonds and chameleon diamonds [which change colour from yellow to green depending on temperature]. I get most excited when it is a rare colour – reds are the most rare, from Australia and South Africa.”

One challenge she was set was sourcing a 10-carat pink diamond for an international client to present to his wife on the birth of their baby daughter – a stone that is probably now worth $5 million and complemented a similar blue diamond he sourced at the birth of his son.

Castelli, who has two children, explains: “To give you an idea of how special these gestures were, pink and blue diamonds are some of the rarest on the planet and finding the pink example was an eight-month assignment, up against two other people engaged by the client.

“I’m also very proud to have sourced a green chameleon diamond for a gentleman to present to his wife recently. The value was relatively small, at less than $1 million, but it shows why I like to think of myself as the queen of diamonds, because I aim to understand and find the right stone or gift for the person or the event.

“I think that feminine intuition, plus my diplomacy, patience and tenaciousness give me an edge in what is still a male-dominated business.”

And with that, she turns and leaves for her next appointment, with a sparkle in her eye.

Updated: March 22, 2023, 4:03 AM