Jessica McCormack has built an empire on her unique ability to inject diamonds and jewellery with attitude, creating pieces that pair as effortlessly with everyday denim as they do with couture.
There’s a reason her designs appear, often without fanfare, on the world’s most stylish women. A scroll of Instagram might see Sienna Miller in Gypset hoops and a white tee, or Rosie Huntington-Whiteley wearing a Ball n Chain necklace with a pear-shaped diamond pendant. Zoë Kravitz, the brand’s official ambassador, is equally an icon of nonchalant, cool-girl style. Each wears McCormack’s jewels the way they wear everything: with an insouciance that feels utterly authentic. This always-present but never overbearing nature makes McCormack’s pieces part of the woman, not just her outfit — fine jewellery that celebrates life as it unfolds, from career wins and bold beginnings to the once-in-a-lifetime milestones worth marking forever.
It’s a philosophy McCormack lives by, “Love and romantic milestones have always been celebrated with jewellery,” she says, “but today, people are much more open to the idea of commemorating success and transformation in the same way.”

With three London boutiques, (Carlos Place, Sloane Street, and a new location in Harrods), and a New York store that opened on Madison Ave earlier this year, McCormack and her team see clients worldwide seeking something to symbolise the moments that matter. “Most of our clients are self-purchasing women celebrating promotions, graduations, and important friendship milestones,” she explains. “When a client associates a piece of JM jewellery with their personal achievement, it’s incredibly rewarding for us.”
“The Gypset hoops are our most iconic piece; they’re often right at the top of people’s wish lists.”
That combination of deeply personal meaning and enduring style is what makes her work resonate so powerfully. “We’re naturally associative,” McCormack says. “Having a piece of jewellery that brings back fond memories is a lovely thing.” This explains why her collections often become part of a lifelong story, evolving alongside the wearer. “I have clients who have built collections over the years that celebrate their achievements,” she notes. “Some have beautiful ring stacks with gold Bamboo and Rope rings alongside eternity bands. Others have collected Ball n Chain pendants; I love seeing them layered together, mixing a Diamond pendant with a Hello Sailor Starfish.”
While each piece is designed to stand alone, McCormack has always been conscious of creating jewellery that can grow with its owner. When asked if the idea of lifelong layering was intentional, she says, “Yes, definitely. You can start with something simple, like a diamond button-back or pearl necklace, and build upon it over time.” That longevity is matched by a commitment to exceptional craftsmanship, ensuring each jewel will stand the test of time and endure for generations. “The quality of the craftsmanship is absolutely vital,” she says. “It’s what makes the piece last and allows it to be worn every day. Finding an exceptional stone to lead the design can transform it into something unforgettable.”

For milestone gifting, some pieces have become go-tos among her clients. The Gypset hoops are often chosen to celebrate work promotions or personal milestones, “They’re our most iconic piece, and so they’re often right at the top of people’s wish lists,” McCormack says. For big birthdays, necklaces take centre stage, “Ball n Chain necklaces are particularly popular because you can then begin to collect the pendants. They make the perfect present, and you become the easiest person to shop for at Christmas!”
Her Beaches collection, with playful yet elegant designs, also resonates with milestone buyers. “The Conch Shell ring or bangle would be the perfect gift to celebrate a birthday or personal achievement,” she suggests, noting that these designs strike a balance between whimsy and timelessness.
“Many of my clients are self-purchasing women who reward their own goals, which I think is really powerful.”
McCormack’s ethos also taps into a wider cultural shift; the rise of self-gifting as a form of self-recognition. “I see more and more people wanting to mark personal milestones that might not have been traditionally celebrated with jewellery before,” she says. “Many of my clients are self-purchasing women who reward their own goals, which I think is really powerful. It is a nod to the idea that one can celebrate their success without being viewed as proud or boastful, it’s now about recognising your own journey and achievements.”

This unapologetic, personal, effortlessly chic attitude is precisely why McCormack’s jewellery has become shorthand for a certain kind of woman: stylish, independent, sentimental, and unafraid of tradition. It’s also why her Instagram is such an effective calling card, showing diamonds styled with everything from vintage denim to sharply tailored blazers. As McCormack puts it, “Our role is to create pieces of the highest quality that are beautiful, timeless, and effortlessly wearable every day.”
Jessica McCormack offers more than just jewellery; her pieces are tangible symbols of life’s most meaningful moments. “An important piece of jewellery often feels appropriately significant enough to mark an important life achievement,” McCormack reflects. “And when that moment is remembered every time you put it on, it becomes priceless.”