Curtis Steiner’s disarmingly blue eyes light up as he pulls an object from inside one of the glass jewelry cases in his eponymous Ballard Avenue shop.

It’s an ornate antique piece: a mourning brooch, he says, though he quickly points out that these were given not only to commemorate death, but also as reminders of loved ones who had moved away. It’s a crosshatched oval, like the lattice top of a pie, made of human hair, ringed in gold, diamonds and black enamel detailing. It’s priced at $6,200—not the most expensive thing in the store, but certainly not the cheapest either. On the back of the brooch, an engraved date reads December 25, 1887—a Christmas gift. “This should be in a museum, not here,” Steiner says. Half-jokingly, he adds, “I figure I’ll be buried with it.”

THOUSAND-YARD STARE: One of Curtis Steiner’s most notable design elements at Deep Dive, a bar in the Amazon Spheres, is a series of glass cloches, illuminated from below, that serve as lights. Each is filled with a different display: this one with a great crested grebe perched atop a 19th century beaded footstool

This beautiful, macabre piece of jewelry is exactly the sort of esoteric treasure people have come to expect from Steiner’s shop—an expression of his unique aesthetic. In November, he will celebrate 20 years as a Ballard Avenue shop owner—first at Souvenir, where he sold his signature cards for 12 years, then at Curtis Steiner (5349 Ballard Ave. NW; 206.297.7116)—a major milestone, considering the seismic shift the neighborhood has undergone around him. “When I opened [Souvenir], people were like, ‘What’re you doing? Nobody goes to Ballard,’” he says. “It wasn’t serious. But it got pretty serious pretty quick.”

People still remember Souvenir for the intricate, saturated window installations Steiner created for the narrow storefront. When some necessary construction on the building forced him to move up the street in 2011, he embraced the gallery atmosphere of the new space, a triangular fishbowl of sorts where “everything has to relate to everything,” he says. “It’s a much bigger story to compose.”

JEWEL TONES :Each of the jewelry cases in Steiner’s Ballard shop have a different look; in one, he uses playing cards to make antique pieces pop

“A lot of people come into my store and can’t quite figure it out,” he says. To be fair, there’s a lot going on: cases of jewelry containing a mix of his own designs and special antique pieces, like that mourning brooch; exhibited work by other artists; large wall displays of his signature cards, which are still priced at only $6.50; and a mix of found objects large and small. Somehow, he makes it not only cohesive, but stylish. Peculiar, yet elegant. “[Customers] know they’re having this experience, but they don’t really know what to do with it. ‘What is this?’ [They] gesture around. It’s the most horrifying and gratifying piece of this.”

Steiner met renowned restaurateur Renee Erickson when she was neither renowned nor a restaurateur. She was a cook at Boat Street Cafe (precursor of Lower Queen Anne’s Boat Street Kitchen) before she took over the restaurant from owner Susan Kaplan, back when it was actually on Boat Street. Steiner was the “very best regular” at that restaurant, Erickson says. At one point, Kaplan commissioned Steiner to illustrate the chalkboard wine list; he drew up some drunken Chihuahuas.

An assortment of insect-inspired jewelry made by Steiner; it’s on display at Deep Dive this summer  alongside other remarkable antique insect jewelry 

That chalkboard menu now hangs in Erickson’s home. Over the years, she and Steiner have become close friends, traveling the world together and celebrating their common interests: art, food, wine, interior design, gardening and generally enjoying life. “When [Renee and I] are together, we roll our eyes at the same things, we embrace the same things,” Steiner says. “It’s just the perfect relationship.”

Every curio at Deep Dive has a story, and Steiner knows them all. One wall has pieces from around the world; Steiner says he thinks of the red Japanese lacquer plate as representing the sun, while the white stone dish from India, pockmarked by acid rain, symbolizes the moon.

Last year, Steiner, an avid gardener and nature lover, was almost exclusively responsible for the look—botanist’s lair meets speakeasy—of Deep Dive (South Lake Union, 620 Lenora St.; 206.900.9390), Erickson’s ultraluxe, and highly anticipated, bar in the Amazon Spheres. Bedecked in rich jewel tones and lined with curios—an antique top-hat sizer, a taxidermy squirrel, a breathtaking crown made entirely of matchsticks—the cocktail bar is the very embodiment of Steiner’s aesthetic: that synthesis of unusual and interesting. “I wanted this place to literally sparkle,” he says, an effect he has accomplished with details like fluttering sequins and iridescent butterfly wings. “I wanted it to feel like magic.”

Although Steiner has consulted on the decor at a few of Erickson’s other restaurants—to a much lesser degree—she says working with him on Deep Dive was “a dream. We have always wanted to be able to offer him the ability to go crazy with an interior of ours, but never really had the means to really let this happen,” she says. Steiner speaks of the Deep Dive project as one does about a magnum opus; he knows he may never again have the opportunity to execute something like this.

Some of Steiner’s favorite pieces can be found in Deep Dive’s back room, like the majestic chandelier he designed in collaboration with local glass artist John Hogan

Deep Dive is a noticeable departure from Erickson’s typically white, classic minimalist spaces, though even in those, she always has a touch of whimsy or punch of color, like the hot pink espresso machine at her General Porpoise doughnut shops. And maybe that’s where Steiner’s influence is the most apparent. “I’ve had some effect on her aesthetic, sure. I’m not sure it would be the same if she didn’t know me,” Steiner says. “But I think her [aesthetic] is a little more consumable than mine. She’s so lucky that she’s got her finger on the pulse [of what consumers want].”

Ironically, the pulse has never really been of much concern to Steiner. He’s happy pursuing his own passion for eccentric objects that tell a story and for drawing others into his orbit. “I think there are people that love to have exactly what their neighbors have: the same clothes, the same furniture, the same jewelry…but I’m not one of those people,” he says. “I like to amuse people.”