Alberto and Stefania Sabbadini’s Milan penthouse is just a few hundred yards from the family’s namesake jewelry store on the celebrated Via Montenapoleone, in the city’s commercial heart—but it might as well be its own private world. Stefania, who helps run the company with their son and CEO, Pierandrea, opens the door wearing a leopard-print coatdress accessorized with yellow enamel pansy earrings and, trembling on her collar, a swarm of Sabbadini bee brooches. Twiggy, the family’s West Highland white terrier—a string of colored beads and a collar around her neck—stands by protectively.

“My hero was Che Guevara—he was purity, not contaminated, when I was a teenager,” Stefania declares, as we pass Let a Thousand Flowers Bloom, a sad yet mesmerizing depiction of Chairman Mao Zedong by the German artist Anselm Kiefer. “The idea of freedom is completely different now. You younger people have many more problems.” The first artwork Alberto bought Stefania was a Marc Chagall gouache that she treasures; they also have a Fernand Legér from early in their marriage. Cohabitating with these acquisitions is a huge turquoise painting with grinning skulls by Jean-Michel Basquiat that dominates the sitting room. On an adjacent wall is Andy Warhol’s 1964 Flowers, and elsewhere there are works by George Condo, Cindy Sherman, and René Magritte. Stefania gravitates toward historical pieces that represent the weight of European culture. “Now Alberto starts buying things I’m not so happy about!” she complains. “I prefer a small, nice painting. But we made a deal. We keep the younger, more contemporary artists in New York, and the other ones here and in Saint Moritz.” One could make the argument that the theme of the Sabbadinis’ art collection is, much like the family itself, eccentricity.

A Zio Paperone, or Scrooge McDuck, from the 1950s.

Photograph by Walter Pfeiffer; Styled by Gianluca Longo.

“Usually, I suggest new artists in New York long before they become known,” pipes up their daughter, Micól. “When I tell my dad, it goes in one ear and out the other. Then someone else tells him about them, and he goes and buys them, five, 10 years later. I could have saved him a lot of money!” Micól, who is 34 but looks like she could be in college, is a fixture on the Milanese social scene. She’s been known to throw birthday and Fashion Week dinners for 150 in the family apartment, followed by treks to the old-school Bar Jamaica and to Plastic, the legendary nightclub, where she has been spotted more than once dancing on tables. She also has a penchant for travel: “I’m wherever there’s sea and surf and kite-surfing and surfers and a hammock and a lot of sand and a beer,” she says.

But Micól is also pursuing her own artistic interests, focused mainly around photography. Her digital collages, assembled from images taken on her many trips, depict fantastical, imaginary landscapes; she has also collaborated with Max Mara to create fabric designs from her ­pictures. She flew to New York to photograph the Women’s March last year, and made T-shirts on the theme of women’s rights for Zadig & Voltaire, with proceeds benefitting Christy Turlington Burns’s nonprofit, Every Mother Counts. She recently met Barack Obama when he came to Milan. “I was like a teenager. I didn’t sleep for two days before, I was so excited. I told him, ‘You can’t disappear, because we really need you now.’ ” (By way of contrast, she once sat next to George Clooney at dinner and had no idea who he was. “I asked him what he did for a living,” she remembers.)

The family began collecting timepieces 25 years ago.

Photograph by Walter Pfeiffer; Styled by Gianluca Longo.

Stefania also confesses to dancing on tables and sofas, albeit at private parties, or even at home, alone. Her dressing room, filled floor to ceiling with racks of couture gowns and Hermès bags, attests to a rich social life. “One of the things that attracted my dad to her,” Micól says, “is that my mom was so elegant. So perfect.” While mother and daughter banter animatedly, Alberto sits working quietly at his desk in the adjoining room, occasionally piping up. He’s palpably proud of, and amused by, the women in his life.

Everything wasn’t always so joyful. During the Second World War, Alberto’s father, Bruno, and mother, Sarita, had to flee Milan. “As Jews, they couldn’t stay in the city,” Stefania says. “They went into hiding in the country. One night, the mayor of the village told them, ‘You are first on the list for the trains. Any luggage you bring with you, they throw away. Wherever you are going, you don’t come back.’ ” The Sabbadinis escaped, walking to the Swiss border—only to find out that it had been closed because of the overwhelming number of refugees. Alberto’s father produced a bag of precious stones, the only thing he had brought with him, to convince the guards that he could support the family. “If it wasn’t for the diamonds, they wouldn’t have gotten through,” Micól says.

The living room, with Damien Hirst’s Lost Hope, 2004, above the sofa, and Victor Brauner’s Transmutation Onirique, 1946, above the fireplace.

Photograph by Walter Pfeiffer; Styled by Gianluca Longo.

Later, Micól places other stones, one by one, in my palm. Cabochon-cut emeralds. Rubies, like little universes formed after the Big Bang. A pale, entrancing diamond. “Internally flawless,” says its documentation, as if it were a pedigree dog. “Fancy Pink. 6.76 carat. Oval Modified Brilliant.” “It could buy you any villa, anywhere in the world,” Micól says.

We are at the Sabbadini store, its quietly luxurious frontage resembling a piece of lacquered japonaiserie. All but the cognoscenti might pass by, unaware of the beauty that lies within. Hermetic double doors guard an oval space with a vaulted ceiling and dark green walls with gold accents, enlivened by a radiating checkerboard-parquet floor inlaid with ebony bees. Green-velvet-lined vitrines beckon with precious objects glittering like fireflies. Opened in 1998, it was the first and only commercial space created by the legendary architect-designer Renzo Mongiardino.

A photograph of Stefania and Alberto Sabbadini from the 1980s.

Photograph by Walter Pfeiffer; Styled by Gianluca Longo.

Celebrated for his opera sets for La Scala, in Milan, and the Royal Opera House, in London; his Oscar-nominated designs for Franco Zeffirelli’s classic films; and his highly composed interiors brimming with lush fabrics, tassels, and trompe l’oeil murals for the likes of Gianni ­Versace, Aristotle Onassis, Gianni Agnelli, and Lee Radziwill, Mongiardino gloriously celebrated Italy’s historical heritage at a time when stark modernism was the norm. It was a ferociously lavish vision that bled the past into the present. His style had, according to his friend the writer and horticulturist Umberto Pasti, “the corrosive breath of melancholy.”

Having found the site on Via Montenapoleone for his new store, Alberto needed to create a spectacular yet tasteful interior. “The space was extremely cold, with no allure,” he says. “I was looking for someone who had the ability to transform it into something unique, elegant, and precious—the elements we look for in our jewelry.” Mongiardino was invited to the Sabbadini showroom—the designer was famous for not working with clients unless they had proved they had their own taste. “He was actually the one who interviewed us, asking us at length about our family, our traditions, our jewelry, what our brand stood for,” Alberto recalls. “As he was leaving, he said we would meet the following day.” That left Alberto and Stefania “very excited but nervous. The next day, he told us he would take the job.”

The interior of the Sabbadini boutique in Milan, designed by Renzo Mongiardino.

Photograph by Walter Pfeiffer; Styled by Gianluca Longo.

Alberto asked Mongiardino what had swayed his mind. Mongiardino had insisted on being shown the Sabbadini workshop, and it was in that extraordinary, almost alchemical space, with its wooden benches and vats of mysterious liquid that tinted gold into yellow, white, or rose, that Mongiardino found the spark that inspired him: an artisanal process he had thought long since lost. (As Micól points out, this type of craft had existed in Milan for more than a thousand years, but Sabbadini is the only jewelry house that still manufactures in central Milan.)

There was also an emotive, almost Proustian invocation. Mongiardino had seen a ring in the showroom that reminded him of one that his mother used to wear. Out of this childhood memory he would build a “treasure chest,” a kind of protective carapace constructed around the timeless, transformative power of precious stones. As fate would have it, this turned out to be Mongiardino’s last commission. The artist died in 1998, at age 81, leaving his disciple, Roberto Peregalli, and his partner, Laura Sartori Rimini, to complete the project.

Stefania Sabbadini (left) and her daughter, Micól Sabbadini, in the living room of their Milan apartment with their West Highland terrier, Twiggy, and Jean-Michel Basquiat’s Equals Pi, 1982. Stefania wears a Marc Jacobs gown and shoes, jewelry from her namesake line. Micól wears Balmain clothing, Sabbadini jewelry, Tom Ford shoes.

Photograph by Walter Pfeiffer; Styled by Gianluca Longo.

That interior became the stage for the Sabbadini jewelry house, ­celebrated for its tiny stones clustered in seamless pavés around single statement gems, its exquisite enamelling of natural motifs ranging from flowers to dogs, and its signature bees, which Alberto designed especially for Stefania. But the work is also absolutely contemporary. Some vivid enamel forms even evoke the Sabbadinis’ love of modern art: It’s hard not to see Warhol’s flowers, or even Jeff Koons’s glossy artifice, in some of their vibrantly colored pieces. Sabbadini expresses individualism, wit, and theatricality. These are glamorous gems you can party in: Micól shows me the clips she had fixed onto her earrings, alongside the usual posts, “so that I don’t lose them when I’m dancing.”

The next day, back in the apartment, Stefania channels a 1980s vibe in a gown by Alberta Ferretti for our photo shoot. She holds her thick blonde hair in a bunch as the camera’s flash reflects on a work by the Brazilian artist Vik Muniz. Then Micól appears in a dramatic knee-length black cape, her hair ravishingly piled up and pushed back, like Jerry Hall sashaying into a Bryan Ferry video. Underneath the cape, she is clad only in fishnets and underwear. “My dad will have a heart attack!” she says.

On cue, Alberto Sabbadini arrives. Reminiscent of a teenager caught singing into a hair brush in front of her bedroom mirror, Micól rushes off to cover up with a modest lavender sweatsuit. The family adjourns to the terrace for lunch: antipasti, chicken, veal, salad, wild strawberries, and sorbet. I sit next to Alberto, a man whose passions emerge slowly, as if delivered from deep within his immaculately tailored dark blue suit. (“My father doesn’t know the meaning of ‘casual,’ ” Micól says.) The conversation turns to the art events happening in the city.

In the library, Vik Muniz’s Napoleon (Or Lampião) (from Pictures of Chocolate), 1997, hangs above the fireplace, with a work from Anselm Kiefer’s series “Let a Thousand Flowers Bloom,” 1998, on the far wall.

Photograph by Walter Pfeiffer; Styled by Gianluca Longo. Shop interior: courtesy of Sabbadini; living room: Guido Taroni; Hirst’s lost hope © Damien Hirst and Science ltd, all rights reserved, Oacs 2018. Library: Guido Taroni; Hair by Davide Diodovich; Makeup by Arianna Campa for NARS Cosmetics at Close Up Milano; Photography Assistant: Torvioll Jashari; Fashion Assistant: Antonio Autorino.

He calls across the table to his wife. “You know who is my lover, don’t you?” Stefania rolls her eyes and says, “Which one?” “My mistress,” Alberto exclaims. “Tracey Emin!” They chat about Gstaad and Saint Moritz, in and out of season. The sun shines. Micól consults her Instagram feed. Down below, on the street, fashion holds sway, reinventing itself every season. But up here, the Sabbadinis hold on to their own set of values. Beauty. Truth. Art.

And dancing.