“It has been challenging but we have learned so much from aluminum,” Ms. Hemmerle said. “Sometimes you need to walk through a new door to find out what is behind it.”

In the construction of the earrings, Mr. Hemmerle said, art connoisseurs may find echoes of the art of Agostino Bonalumi, Paolo Scheggi and Enrico Castellani, postwar Italian artists known for their spatial experimentation and whose work inspired the jewelry.

“The Hemmerles use cultural themes as the inspiration for their unique collections,” Max Fawcett, the head of jewels at Christie’s Geneva, wrote in an email. “They have created their own iconic style which resonates with collectors, easily recognizable among the huge variety of choices that are on offer today.”

Hemmerle does not disclose prices, and its jewelry rarely appears at auction. In November, Christie’s Geneva sold a pair of pinkish-red spinel earrings and a matching ring by Hemmerle for a total of 541,800 Swiss francs (about $612,500), far exceeding the combined presale high estimate of 295,000 francs.

Hemmerle produces only about 200 pieces a year, each made only once, and typically each piece’s fabrication requires more than 500 hours of work. It has had its own workshop since its founding, but the current location, not far from Maximilianstrasse, opened in 1999. It now employs 20 master goldsmiths, three of whom are gem setters, and two apprentices, many of whom moved to Munich to work for the company. “We have eight different nationalities in the workshop and 13 in the company,” Mr. Hemmerle said.

Since 2016, a spacious loft-like area on the top floor of the workshop has offered clients a way to see firsthand how Hemmerle pieces are made, and the artisans can meet the people who will wear their work. Afterwards, refreshments by a Michelin-star chef such as Tohru Nakamura or Tim Raue are served.

“This makes for a very special human connection,” Mr. Hemmerle said. “For us, it is all about creating unforgettable moments.”